Oslo Ladegård (Manor House) is situated in Gamlebyen, the oldest part of Oslo. Ladegården with its baroque garden lies in the midst of ruins dating from the Middle Ages. The mansion is built on the remains of Bishop Nikolas' 13th-century castle, and one of his halls is today a part of the cellar. The bishop lived here till 1554. At the end of the 1500s a Renaissance building was erected on the old walls, but the baroque building dates back to around 1720. Guided tours are offered in the summer, and concerts every second Wednesday.