Bilstein, Mountain summit in Brilon, Germany

The Bilstein is a 622-metre hill on the southern edge of the Briloner Höhen, about 4 km east of Brilon, with the Hoppecke flowing at its foot. On its summit, excavated in 2006, stood the "Warth off Beilstein", a watchtower of the Briloner Landwehr: a four-metre-wide tower stump of mortared rubble stone up to 2.70 m high, set on a five-metre foundation sunk into the rock, with an external staircase 0.6 m wide.

The summit was the site of the "Warth off Beilstein", a watchtower probably built in the 14th to early 15th century as part of the Briloner Landwehr, a defensive line of the town of Brilon. The tower is first mentioned in writing around 1480. In summer 2006 an excavation by Archbau, funded by the quarry owner DEUBA Baustoffe, uncovered a tower stump preserved up to 2.70 m high beneath a large pile of rubble. The monument was then destroyed despite citizen protests, and the stones were cleared away by the town of Brilon.

The name Bilstein refers to the quartzite rock of the summit, and the hill gave its name to the Bilsteinwarte watchtower. In 2006, excavations uncovered a mill game scratched into a slate slab and fragments of a clay signal horn (Aachhorn). The tower stump was later removed for the quarry expansion despite citizen protests, and the stones were cleared by the town of Brilon.

Several marked hiking trails start from the parking area near Brilon and lead to the summit. Along the way, visitors find regularly placed benches and direction signs to help them navigate.

The 2006 excavation found a mill game scratched into a slate slab and fragments of a clay signal horn (Aachhorn) beside the tower stump. The watchtower itself, the "Warth off Beilstein", was quarried away despite citizen protests; Brilon had its stones cleared for reuse.