Felsenburg castle was probably built in the 12th century for the Freiherr of Kien. The castle was built on a rocky spire above the road over the Gemmi pass into Valais. It was inherited, along with the rest of the Herrschaft of Frutigen, by the Freiherr of Wädenswil in 1290. The Freiherr of Turn acquired it from Wädenswil in 1312. It was mentioned in a record in 1339 as the castrum de Petra. It was again mentioned in 1368 as Stein, German for Stone. In 1400, Bern acquired the castle along with the rest of the Herrschaft. They abandoned Felsenburg and allowed it fall into ruin.
Currently, only the rectangular main tower and remnants of the outer walls are still standing.
References:The Jan Hus Memorial stands at one end of Old Town Square. The huge monument depicts victorious Hussite warriors and Protestants who were forced into exile 200 years after Hus, and a young mother who symbolises national rebirth. The monument was so large that the sculptor designed and built his own villa and studio where the work could be carried out. It was unveiled in 1915 to commemorate the 500th anniversary of Jan Hus' martyrdom. The memorial was designed by Ladislav Šaloun and paid for solely by public donations.
Born in 1369, Hus became an influential religious thinker, philosopher, and reformer in Prague. He was a key predecessor to the Protestant movement of the sixteenth century. In his works he criticized religious moral decay of the Catholic Church. Accordingly, the Czech patriot Hus believed that mass should be given in the vernacular, or local language, rather than in Latin. He was inspired by the teachings of John Wycliffe.