Feldberg Tower

In the 1950s, the former Southwest Radio at Seebuck built a 45 m high television tower with a viewing platform, which was used as a base network transmitter location for radio and television. However, this television tower was no longer enough to meet the radio-technical requirements of the new millennium, and in 2003 it was replaced by a new 82-meter-high reinforced concrete tower without a viewing platform. The community resisted successfully the demolition of the old radio tower, which is now used without an antenna as a lookout tower and since July 2013 houses a museum for Black Forest ham.

In good conditions you can look up there for up to 240km. Great views of various mountain ranges, including the Zugspitze and Mont Blanc is visible from there.
Also, the numerous runs with the MTB I can only recommend

There is a ham museum in the tower