Hamrštejn (although it is a ruin of castle) is a popular tourist destination between Liberec and Chrastava. It is well accessible by train (Machnín Hrad stop) or by bike along the No. 20 Odra-Neisse. Go to a little sightseeing trip, along the trail there are educational boards.
Castle ruins of HamrštejnGPSChrastavaINFO