Scattered across the hills around the little town of San Andrés de Pisimbalá, Tierradentro's Parque Arqueológico includes four tomb sites, an above-ground statuary and two museums. Tickets for the Parque Arqueológico are inside the museum complex, a 25-minute walk from the town. You're given a 'passport,' valid for two consecutive days, enabling entrance to all sites, accessible via a 14km walk. Visit the museums before the tombs, as there's not much in the way of explanation at the sites themselves.

　　Measuring from 2m to 7m in diameter, the tombs are scooped out of the soft volcanic rock that forms the region's undulating hillsides. They vary widely in depth; some are just below ground level, while others are as deep as 9m, reachable via knee-killing stone steps. The domed ceilings of the largest tombs are supported by pillars. Many are painted with riotous red and black geometric motifs on white backgrounds, others with inquisitive human faces and animal forms.

　　Little is known about the people who built the tombs and the statues – the Páez (or Nasa) indigenous group that lives in the area today is not thought to be connected to the ruins. Most likely they were of different cultures, and the people who scooped out the tombs preceded those who carved the statues. Some researchers place the 'tomb' civilization somewhere between the 7th and 9th centuries AD, with the tombs reserved for the elite, and shallow pits holding the bodies of their servants, while the 'statue' culture appears to be related to the later phase of San Agustín development, estimated to have taken place some 500 years later.