Set within a complex of two churches; the 15th century church of Santo António dos Frades and Igreja dos Terceiros - just to the south of the town centre, is the Museu dos Terceiros or Museum of the Third Order. This is in part a museum of sacred art but it the churches themselves also from much of the interest.
Both church interiors are predominantly 17th and 18th century and in keeping with the period the interiors are fine examples of Baroque design. Altarpieces, pulpits and pelmet are of Rococo design and there is some beautifully painted wood panelling in the sacristy. Along with a number of attached chapels there is cloister and garden.
The museum collection is housed on an upper floor and contains many artworks which were transferred from the Igreja Matriz after it was renovated in the 1970s. These mostly consist of 18th century sculptures and paintings but there are some medieval pieces too.