The archaeological area of Tierradentro, with its complex of hypogeal, are a unique testimony to the everyday life and ritual of a developed and stable society. It also reveals the social complexity and cultural wealth of a pre-Hispanic society in the northern Andean region of South America.
The National Archaeological Park of Tierradentro is located in southwestern Colombia within the Cordillera Central of the Colombian Andes, in the municipality of Inzá, department of Cauca.
Four areas, dispersed over a few square kilometers, make up the archaeological park: Alto de San Andrés, Alto de Segovia, Alto del Duende, El Tablón and as a site of importance but outside the park boundary the Alto del Aguacate. The park contains all known monumental shaft and chamber tombs of Tierradentro culture, the largest and most elaborate tombs of their kind.
The area holds the largest concentration of pre-Columbian monumental shaft tombs with side chambers, known as hypogea, which were carved in the volcanic tuff below hilltops and mountain ridges. The structures, some measuring up to 12 m (40 ft) wide and 7 m (23 ft) deep, were made from 600 to 900 AD, and served as collective secondary burial for elite groups. The degree of complexity achieved by the architecture of these tombs, with chambers that resemble the interior of large houses, is evident in the admirable carving in tuff of the stairs that give access to a lobby and the chamber, as well as in the skilful placement of core and perimeter columns that required very careful planning.
The tombs are often decorated with polychrome murals with elaborate geometric, zoomorphic and anthropomorphic designs in red and black paint on a white background, and the chambers of the more impressive underground structures were also decorated with elaborate anthropomorphic carvings. The smaller hypogea vary from 2.5 m to 7 m (8 to 12 ft) in depth, with oval floors 2.5-3 m (8-10 ft) wide, while the chambers of the largest examples may be 10-12 m (33-40 ft) wide. Most impressive of the latter are those with two or three free-standing central columns and several decorated pilasters along the walls with niches between them.
The symbolic symmetry achieved between the houses of the living above ground and the underground hypogea for the dead, by means of a limited but elegant number of elements, not only conveys an aesthetic sensation but also evokes a powerful image of the importance of a new stage into which the deceased has entered and the continuity between life and death, between the living and the ancestors.
The present state of archaeological and anthropological knowledge suggests that the builders of the hypogea (underground tombs) lived in the mountain slopes and valleys in the area. In the valleys they established small settlements whereas on the hillsides settlement was dispersed, close to the fields. The oval-plan residential sites were built on artificial terraces, with rammed earth floors. The wooden frames were filled with wattle-and-daub and the roofs were thatched. There were no internal divisions and there was a single combustion zone, with wooden benches for sleeping.
The magnitude of the underground works and the way in which human remains were disposed inside the hypogea indicate the existence of a hierarchical social and political structure based on chiefs with priestly functions. The stone statues of the Tierradentro region are of great importance. They are carved from stone of volcanic origin and represent standing human figures, with their upper limbs placed on their chests. Masculine figures have banded head-dresses, long cloths and various adornments whereas female figures wear turbans, sleeveless blouses and skirts. There are feline and amphibious representations manifested in sculptures.
Underground tombs with side chambers have been found over the whole of America, from Mexico to north-western Argentina, but their largest concentration is in Colombia. However, it is not only the number and concentration of these tombs at Tierradentro that is unique but also their structural and internal features.