This complex limits the Great Plaza to the north. It is a basal platform of enormous dimensions composed of two bodies. It houses several architectural complexes dedicated to ceremonial activities.

Stela 9: It stands out among others found in Monte Alban for the numerous glyphs (signs of Mayan writing) carved on its surface.

Sunken Courtyard: It is an inheritance of the Teotihuacan architecture, but with its own dimensions and characteristics. It is the most representative of period III, since it meant emptying a space in order to create a collective plaza for the different temples around; in fact, it was designed to complement the ceremonial functions of these temples. The sunken patio measures 50 m on each side and 3 m in height; it has a square floor plan with stairways on its four sides and two foundations to the east and west. In its center there is a square adoratory with stairways to the north and east. At the beginning of the thirties of the XX century, Alfonso Caso explored this patio and found a drainage, a series of subways, Stela 10 and a shrine with an offering.

Ball Game: The ball game was a common ritual practice among Mesoamerican pre-Columbian peoples. It was carried out in daily life and in religious celebrations; it served to resolve conflicts of diverse nature: land disputes, tribute, commercial controls and others. This Ball Court was built approximately 100 years B.C. and explored from 1933 to 1935 under the direction of Alfonso Caso and his team. Five ball courts were built in Monte Alban, which confirms its importance at regional level. Their shape is typical of ball games, that is, a court with a double T-shaped floor plan. The long section is oriented approximately north-south, delimited by slopes that form, at the north and south ends, the short sections or heads, oriented east-west. The court is sunken in relation to the rest of the building, so it has an access stairway and measures 26 m long by 5 m wide; in the central section, at the level of the court, there is a stone circle interpreted as a marker; in the northeast and southeast corners of the transversal patios there are rectangular niches whose function is unknown.

Residence of Tomb 103: Unlike other residences in this city, which house tombs inside, this one contains at least four (numbers 110, 112, 103 and another s/n), which gives it the character of a family crypt. The main tomb has polychrome mural painting and its entrance is oriented to the west. This housing complex has accesses, each one oriented towards the cardinal points, in addition to a system of rooms with their own patios. It is surrounded by other burials of smaller dimensions, which makes it a true necropolis of the years 500 to 800.

Residence of Tomb 104: This important tomb is located towards the corner of the North Platform, under the western patio of the building that limits towards this point. Its façade was ornamented with a double scapular motif (combining vertical and horizontal lines in two superimposed panels in the form of moldings, an element that in the Oaxacan region has been called double scapular panel). In the central part of the tomb, in a niche, was placed an urn of Cocijo, god of rain and thunder, seated on a jaguar-headed throne.

Mural of Tomb 104, unfolded: The decoration of the chamber presents, on the left (south wall) an old male figure holding a bag with copal or corn grains, and above the niche an offering box was painted on which a bird with a corn grain in its beak is perched. It is followed by a cartouche composed of two dates: “2 Serpent” and “5 Serpent”; under this inscription there is another offering box. At the back of the tomb (west side), a human face emerges from the “jaws of the sky” with the inscription “5 Turquoise”; it is thought that this representation corresponds to an ancestor of the lineage of the dead. On the right wall (north), another male figure also holds a bag with copal or corn kernels, but above the niche there is a “sacrificial heart” and, above, the glyph “1 Lightning”. Near the back wall the dates or calendrical names “5 Owl” and “5 Lightning” are read, which could refer to ancestors of the deceased.

Residence of Tomb 105: The association with other constructions, among them the Small Ballgame and smaller housing units, suggests areas or specific sectors within the city, perhaps grouped as elite neighborhoods. This palace is located in the northeast sector of the site, was built between 500 and 800 and is one of the largest and most luxurious in the city. The tomb is undoubtedly one of the most remarkable funerary constructions in Monte Albán, not only because its painted walls are well preserved, but also because of its elaborate designs.

Mural of Tomb 105, unfolded: It has representations of the gods of rain and corn, many of them with the scroll that indicates that they speak or sing. Some show the conventional face of the old men, with a very developed beard, and exhibit a multitude of attributes in the headdresses, formed by masks, feathers and hieroglyphics, which probably indicate their names. The painting of a drawing, much more correct than that of Tomb 104, has a general reddish tint, more accentuated in the bodies of the figures. The colors blue, yellow, green, pink and black were used in the dresses and girdles.

Building A: Rectangular structure composed of four staggered sections. The first wall corresponds to the plinth and is composed of vertical walls decorated with double scapular panels. The main façade faces west and has a monumental staircase delimited by wide alfardas and interrupted by a landing, from which vertical walls are deployed. The rear façade adjoins the east side of the North Platform, where, at the beginning of the first body, there is a narrow alley that in turn contains a sidewalk attached to the boards. The rest of the sides are formed by sloping walls made of irregular core-type stone, and most of them are reconstructed.

Building II: Structure of the last constructive stage that presents a T-shaped plant and consists of two staggered bodies with masonry walls. The main facade is preceded by a sidewalk oriented toward the west, and has a stairway delimited by alfardas decorated with scapular type boards. Below the level of the top of the basement is preserved the substructure of a rectangular temple, deployed on a small platform, which still retains seven pilasters. On the south side is the entrance to a spiral staircase, which penetrates into the interior of the structure communicating the lower part with the top of the basement.

Two Doors Building: It is part of the Geodesic Vertex complex. Its plan in the high part is atypical of Monte Albán, since it has two accesses: one to the south flanked by columns of which only one remains, and the other to the north, narrower, that communicates with a small patio. It has an apparent function of transition between the area of the sunken patio and the set of the Geodesic Vertex. It is seated on two platforms, the lower one with a staircase delimited by sloping alfardas and decorated panels; the second, smaller one, also has alfardas. Previous explorations exposed a tunnel 6 m deep and 9 m long. On the western exterior there is a sloping wall that repeats the shape of the one found in the interior, but without a panel, and together with the back of Roman Building I forms a courtyard open to the west.

Building X: It has a rectangular T-shaped floor plan and has a wide staircase in the central part, without alfardas, which runs along the entire length of the façade. It preserves the remains of a room also of rectangular plan, with narrow access and without columns. At the top is the temple, divided into two well-defined architectural spaces: a large vestibule delimited by two columns and the temple itself higher up (it exceeds it by 15 cm).

It is a very large structure that closes the plaza. It is conformed by two bodies and from the superior part the great ceremonial square can be observed integrally. In the lower part and in the corners are embedded several stelae with reliefs of zoomorphic figures. It is the highest construction of the city, with 40 m of height. It has an almost quadrangular plan of approximately 140 m per side. Built during the heyday of Monte Alban, in its lower part there are some stelae with glyphs of the pre-Columbian Zapotec writing, one of the first to appear in Mesoamerica. In the upper part of the platform, where the visiting public can access by a stairway from the north side of the construction, there are two small mounds that fulfilled ceremonial functions. The large plaza became a market space, where merchants from the surrounding regions, or even from farther away, congregated in Monte Albán. All kinds of products were traded here, such as plants, foodstuffs and objects destined for veneration.

Adoratory: Related to Building P to the east and the set of Buildings G, H and I to the west, the Central Adoratory was a very important space for the Zapotecs in the celebration of the beginning of the rainy season. The shrine functioned as a rainwater reservoir and underwent several modifications throughout the development of the city, as two stages of construction are clearly visible. The first is connected with two tunnels or drains on its east and west sides, which are linked to higher levels of Building II to the east, and Building H to the west. The second is the cistern we see today, whose center has an altar where offerings were placed.

Stela 18: It dates from the Classic period and is considered an astronomical instrument similar to those found in other civilizations. Its most evident function is to reflect, by means of the position of its shadow, the moment when the sun is at noon. Made of sandstone, it is 5.20 m high and is arranged in such a way that, along both sides, it indicates with great precision the direction of the astronomical north. It also has some calendrical glyphs. It was discovered by Alfonso Caso during the seventh and eighth seasons of explorations in Monte Alban, between 1937 and 1939.

It is a large square of 300 x 200 m divided into two areas by a line of buildings, three of them joined while the fourth is independent. On the north and south sides there are two large platforms with more buildings. This mound, called D by archaeologists, has a rectangular front part composed of three staggered bodies with vertical faces, and a strange back part, ending in an acute angle and crossed by a long and narrow corridor. It is probable that this construction functioned as an astronomical observatory. On the west side of the square were erected three buildings of great size and importance, of which the one in the center is totally different. The central building is called the Mound of the Dancers, because in its interior decoration are the famous “dancers” of Monte Alban, of clear Olmec influence. On its north side rises the structure called System F, a construction composed of a pyramidal structure of square base with 36 m of side. Its upper platform is accessed by a staircase of two sections limited by alfardas. In front is a square with a central shrine. Finally, to the south of the Mound of the Dancers rises Mound M. To the east of the square there are several smaller constructions, among which the most important is the Ball Court, close to the North Platform.

Building K: It is part of the architectural complex called System IV, which is formed by a rectangular platform that closes the complex on the east, an open patio delimited by a perimeter wall, a quadrangular shrine located in the center of the patio and a stepped pyramidal base that limits the complex on the west side. Winter classifies this type of complexes as “Temple-Patio-Adoratory” and, according to the author, they are residential structures. Regarding its constructive characteristics, it is a pyramidal base with a rectangular plan formed by three staggered bodies, oriented on the east-west axis; the main façade is composed of a monumental stairway delimited by wide alfardas that end in the second body of the structure. The upper part of the basement is crowned by a rectangular temple oriented north-south; this enclosure presents different superimpositions, as can be observed by the remains of architectural elements attached around the exterior parameters. It has a portico that is accessed through a slope (sidewalk) on which four stone columns were deployed that probably supported a roof. The exploration tunnels practiced some time ago show the different older constructive stages, of which a megalithic wall of Monte Albán's epoch I stands out.

Building H: This building is integrated by a foundation of two bodies and three structures in the upper part. The first is a rectangular enclosure that is located on top of a platform topped by boards in the center of a temple formed by three compartments. Towards the east and west sides there are stairways. The south side is decorated with a thick molding and underneath there is a row of stone discs similar to those of the Ball Game. On the same area there is a narrow stairway that communicates with Building I and a well whose function is not yet defined, which in the upper part has a kind of chimney with a certain resemblance to the one found inside the stairway of Building P. In this building H is tomb 165, located in the area of the portico. Towards the north and south ends are two small buildings that Marquina called “two one-room temples” with columns in front of the door.

The Palace: It is a residential building of the IIIA and IIIB-IV periods built on a platform with a double scapular type board. It is accessed by a wide staircase leading to a door with a monolithic lintel facing the main square with a “blind entrance” that prevents seeing inside. The interior is divided by several walls that form rooms around a central courtyard. Here there is a small quadrangular altar and the entrance to a tunnel that has not been fully explored. It was believed in the existence of a tomb in this site, but later it was verified that it was the partial adaptation of a previous building, which consisted of a corridor with two lateral wings.

Building of Los Danzantes: It is a platform with a rectangular floor plan, whose walls are built on a slope at the top. It is integrated by three constructions. In the central area there is a palatial enclosure of quadrangular plant composed by seven rooms distributed around a patio of similar plant, and in the northeast and southeast corners of the building there are two quartiers or temples of rectangular plant. The facade of both is oriented to the center of the building. These three structures are decorated with double scapular type panels. Two tombs, number 60 and 69, according to Alfonso Caso's classification, can also be seen in the upper part of the building. In the northeast corner there is an exploration tunnel, which is the product of previous interventions. This Building L has been recognized as one of the oldest constructions present in the Main Plaza of Monte Alban.

Gallery of the Dancers: It is built with large blocks of engraved stones, which belong to the sculptural group of anthropomorphic characters that have similar characteristics to those of the Olmec culture; this substructure can be appreciated at the level of the base of the platform.

Building J, The Observatory: The peculiar design of this building is of great importance due to its formal and architectural characteristics. Its orientation is different with respect to the other buildings of Monte Albán, which have a north, south, east or west orientation, while this one is oriented towards the northeast. Its current architectural plan is the product of several superimpositions and has the shape of an arrowhead. The rear facade, which ends at an angle, makes its lateral faces form a geometric figure similar to a pentagon. This substructure is covered with huge stones engraved with different motifs. Due to the orientation of its walls and corridors, it is highly probable that this building was used as an astronomical observatory. The west and east facades, as well as the walls that formed the access of the last constructive stage, present large engraved slabs of the dancing type belonging to previous stages, and that were reused due to the architectural superposition that the building had. The south and southwest façades present the sequence of slabs called “of Conquest”, corresponding to Period II.