The monastic church of the Assumption of Our Lady was founded around the year 1300, replacing a Romanesque one. The rich and influential Sedlec monastery, founded in 1142, located next to the silver deposits, had sufficient resources for the construction of the church, which was finished in 30 years. In 1421 it was burned down by Hussites and for 300 years there only was a ruin of the church until 1700 when it was re-built by Jan Blažej Santini Aichl who created a very original synthesis of Baroque and Gothic style. The church has a shape of Latin cross. The interiors of the church are mostly Baroque.
The cathedral treasury conceals the original Sedlec monstrance, one of the oldest preserved Gothic monstrances worldwide. The monstrance is also believed to be the third most precious jewel of Czech Republic. It is also only in Sedlec, where you can actually go to the cinema, which is placed right inside the church.