Ingolstadt is a green city with numerous parks, green spaces and forests. The most prominent of these is the "Glacis", formerly an open space in front of the city walls, now surrounding the historic city center. It functions as a "green belt" and a buffer area between traffic, residential areas and schools. It is possible to traverse it using spacious paths for pedestrians and cyclists, with a good view of the site of the former fortifications, including a well-preserved section of the ditch. The biggest park in the city, at about 50 acres, is the Klenzepark, which contained the former Ingolstadt State Fortress, and was the site of the Landesgartenschau in 1992, is also a part of the Glacis. Klenzepark is south of the Danube river, opposite the Ingolstadt old town. In the warm seasons about 100,000 visitors use the park every month, mostly young people. While about 75% of the park visitors come from Ingolstadt and the surrounding area, the remaining approximately 25% travel from more distant places.