The Igreja de São João de Alporão is a 12th-century Romanesque-Gothic church that now serves as Santarém's archaeology and sacred art museum. The building itself is a fine example of the transition from Romanesque to Gothic architecture, with carved capitals and pointed arches in the nave.
The collection includes Roman artifacts from Scallabis (the Roman name for Santarém), medieval sculptural fragments, and the remarkable Gothic tomb of Duarte de Menezes — one of the most unusual memorials in Portugal. The church is small and the visit won't take more than 45 minutes, but the quality of what's here justifies the entrance fee. It is one of the highlights of a day in Santarém.