1764, and ended all attempts at rebuilding. Later on, the castle was misused as a quarry; stones from the castle were taken to build new houses in Heidelberg. This was stopped in 1800 by Count Charles de Graimberg, who then began the process of preserving the castle. Although the interior is in Gothic style, the King's Hall was not built until 1934. Today, the hall is used for festivities, e.g. dinner banquets, balls and theatre performances. During the Heidelberg Castle Festival in the summer, the courtyard is the site of open air musicals, operas, theatre performances, and classical concerts performed by the Heidelberg Philharmonics. The castle is surrounded by a park, where the famous poet Johann von Goethe once walked. The Heidelberger Bergbahn funicular railway runs from Kornmakt to the summit of the Königstuhl via the castle. The castle looks over the entire city of Heidelberg and the Neckar Valley. Philosophers' Walk On the northern side of the Neckar is located the Heiligenberg (Saints' Mountain), along the side of which runs the Philosophers' Walk (), with scenic views of the old town and castle. Traditionally, Heidelberg's philosophers and university professors would walk and talk along the pathway. Farther up the mountain lie the ruined 11th-century Monastery of St. Michael, the smaller Monastery of St. Stephen, a Nazi-era amphitheater, the so-called Pagan's hole and the remains of an earthen Celtic hill fort from the 4th century BC. Heidelberg churches There are many historical churches in Heidelberg and its surroundings. The Church of the Holy Spirit has been shared over the centuries since the Protestant Reformation by both Catholics and Protestants. It is one of the few buildings to survive the many wars during the past centuries. It was rebuilt after the French set fire to it in 1709 during the War of the Palatinian Succession. The church has remains of the tombs and epitaphs of the past Palatinate electors. This Church stands in the Marktplatz next to the seat of local government. In 1720, Karl III Philip, Elector Palatine came into conflict with the town's Protestants as a result of giving the Church of the Holy Spirit exclusively to the Catholics for their use. It had previously been split by a partition and used by both congregations. Due to pressure by the mostly Protestant powers of Prussia, Holland, and Sweden, Prince Karl III Philip gave way and repartitioned the church for