Church of St. Martin in the Wall, Medieval church building in Old Town, Czech Republic

The Church of St. Martin in the Wall is a Gothic church with a Romanesque core, its south wall once built against Prague's Old Town fortifications. Rough grey and brown masonry with lighter quoins carries a red-tiled roof; a slender dark spire with a bulbous base rises from the ridge, and a pink "MUSEUM" sign sits in the paving. Inside, dark timber ribs radiate over white plaster walls above tall pointed arches, with blue gridded windows, stone niches holding dark statues, and a cloth-draped stone altar.

The church was built between 1178 and 1187 in the village of Újezd, which after 1187 was called Újezd u svatého Martina. When the Old Town walls were built in the 1230s, the south wall was attached to them, giving the church the name "in the wall".

The church belongs to the Evangelical Church of Czech Brethren. Besides morning services of the German congregation, evening services in Czech are held here, tied to the Protestant theological faculty and Prague's Protestant youth; a different preacher appears each Sunday evening, a tradition of the open pulpit with no parallel in the country.

The church stands in the Old Town near the site of the former St. Martin's Gate, its south wall once abutting the town fortification. Enter from the north side, where the Baroque portal of 1779 faces the street. The pink "MUSEUM" sign set into the paving marks the entrance.

The presbytery vault, finished in the 1360s, is counted among the oldest rib vaults in the country; its ribs spring from pyramidal consoles carved with mascarons, and roses and a star sit on the keystones. A ledge runs beneath the windows around the gallery.