The Complejo de Belén is a large colonial complex built in the early 18th century, comprising the Iglesia de Belén, a former hospital, and two museums. The church is the centrepiece — its baroque facade, carved from the golden volcanic stone that characterizes Cajamarca's colonial buildings, is the most elaborate in the region. Inside, the proportions are generous and the carved stone ceiling of the main nave is remarkable.
The complex was built as a hospital and church under the Spanish colonial administration. The former women's hospital building now houses the Archaeological Museum, with pre-Inca and Inca ceramics, textiles, and metalwork from the region. The adjacent building contains the Medical and Anthropological Museum, covering local history and ethnography. A single ticket covers all three museums in the complex.