Helleberg, Mountain summit in Westerwald, Germany

Helleberg is a 491.3 m high mountain of the Westerwald, not the Rheinisches Schiefergebirge, located in the municipality of Weidenhahn. Its summit area holds the Helleberg observation tower, built in 1998, and an open-air stage with a natural tribune added in 2006. The upper slopes are wooded, and the mountain falls away north and west toward the Sayn.

During the Cold War, the mountain served as a strategic defense location with a radar installation for air surveillance. This military use shaped the site for several decades before the facility was eventually decommissioned.

The mountain serves as a gathering place for local communities, hosting regular concerts and cultural events throughout the seasons. The open-air stage draws visitors from the region who come to enjoy performances in this natural setting.

The B8 crosses the upper slopes about 250 m southwest of the summit, reaching 463.7 m there. A side road branches off at 458.5 m; it is closed to public traffic and serves hikers as the route to the top. The tower platform at 521.3 m is reached on foot.

The 1998 tower stands a few metres northwest of the summit, and its viewing platform sits at 521.3 metres, higher than the 491.3-metre mountain itself. Mobile phone antennas and a weather station are mounted above the platform. On clear days the view reaches the Westerwälder Seenplatte, the Eifel, the Vogelsberg and the Taunus.