One real surprising park we visited in Czech been the Adršpach-Teplice Rocks. The rocks are an unusual set of sandstone formations covering 17 km2. They are named after two municipalities: Adršpach, and Teplice nad Metují. The park offers several hiking parks, from simple to challenging. The park is really stunning, and I never saw something like that before. Even that it can become crowded, it is completely worth to go. May choose a weekday, in the morning hours.