tairona In the northern part of Colombia, around the Sierra Nevada de Santa Marta, crowned by the Colón peak, in the area bounded by the eternal snows at 6.000 m and the sea, lived the Tairona nation. The varied climate favoured agriculture, for which stepped, irrigated terraces were built descending to the sea. Their stone architecture, perhaps the most important from precolumbian times, comprises roads, bridges, stairways and reservoirs in dressed stone, leading to the perfectly designed houses and markets on the slopes of the hills. The goldwork consists of objects of personal and ceremonial use, which has been found in the tombs, in large urns employed for secondary burials. Goldwork, which was often modelled in clay and carbon later covered with gold, was very realistic, especially when tribal chiefs or animals were portrayed. The crowns and diadems, bells, lower lip plugs, rattles, nosepieces, earrings and pendants show great delicacy. Special care was taken in making necklaces of golden frogs. The frog was for them the centre of the cosmos and a symbol of water and fertility. The cornelian beads were used as offerings, and used in divination. Their religious and philosophical beliefs still survive in the groups which inhabit the high Sierra.