The Schlosskirche (Castle Church) in Wittenberg and the adjacent castle were built between 1489 and 1509 on behalf of Elector Frederick the Wise. In 1517 Martin Luther, who was on the theological faculty of the University of Wittenberg, published his 95 Theses against the abuse of the sale of indulgences by nailing them on the main door of the Schlosskirche. Today, about 110 parishioners belong to the Castle Church Congregation. The building is currently being renovated and will reopen in its old splendor in the course of 2016. The Schlosskirche also serves as an important concert venue and hosts many choral and organ concerts throughout the year. Its organ was built by Friedrich Ladegast from Weißenfels in 1863. It was reconstructed and extended in 1994 and has 4 manuals and 3500 pipes.