Church of the Nativity of the Virgin Mary, Religious monument in Mrtník, Czech Republic.

The Church of the Nativity of the Virgin Mary in Mrtník has a Gothic presbytery from the 1350s with walls 1.1 to 1.3 metres thick and five Gothic windows, some retaining their original jambs. The Baroque nave from the 18th century has a flat stuccoed ceiling and a western gallery under a lunette vault. A massive square tower adjoins the presbytery on the north side.

The first church in Mrtník probably stood on the site of a pagan sanctuary. In 1352 Charles IV elevated the mining chapel to a plebanium with a parish priest. In 1568 Jiří Pešík of Komárov had the Gothic church rebuilt in Baroque style, adding a new rectory and one of the oldest schools in the district. Austrian soldiers removed the six-ton bell donated in 1675 by Count Bernard of Martinice in August 1917.

The church holds the tomb of the Pešík family of Komárov, who rebuilt it in 1568, and the adjacent cemetery holds the remains of miners and ironworkers from the Jedová hora mines. The ironworks at Komárov, founded by the Pešíks, supplied the church in 1880 with a painted cast-iron Stations of the Cross, pews with cast-iron sides and a cast-iron baptismal font lid.

The church stands in Mrtník, part of Hvozdec in the Beroun district, with the massive square tower attached to the north side of the presbytery. A spiral stone staircase inside the tower links its floors, lit only by narrow windows. The building is a listed cultural monument, so access to the interior depends on services and parish arrangements.

The six-ton bell donated in 1675 by Count Bernard of Martinice was smashed and taken away by Austrian soldiers in August 1917; the tower now holds a replica. The original Baroque organ from the second half of the 18th century survives with mechanical action, enlarged in 1898 by Prague organ builder Petr Emanuel Štěpán.