Temple of the Masonry Altars (B-4)

17.7646°N, 88.3475°W.

The Temple of the Masonry Altars, designated Structure B-4, is the largest pyramid at Altun Ha in the coastal plain of north-central Belize. Built in the Early Classic around 550 CE and modified through the eighth century, it rises 16 metres in tiered courses of dressed limestone with a wide central staircase. The structure takes its name from the small altars on each of its terraces. In 1968 archaeologist David Pendergast recovered from the summit shrine the largest carved jade object known from the Maya world — a 4.42 kg head of the Sun God K'inich Ajaw, now the national symbol of Belize and held at the Central Bank in Belmopan. The site sits 50 km north of modern Belize City, near the coastal trade routes that linked the Maya lowlands to the Caribbean.

The Temple of the Masonry Altars is a building whose interior held a piece of jade larger than any other ever pulled out of a Maya pyramid.