The first fortifications were built as early as 1050. The Frohburg ruins were the ancestral seat of the Counts of Froburg. The castle had been uninhabited since the 14th century and subsequently fell into disrepair. It is one of the largest of its kind and is designated as a national heritage site. The castle is one of the most thoroughly researched ruins in Switzerland.
The Froburg Restaurant is located about 10 minutes above the Frohburg ruins.
(Content from https://oltentourismus.ch/de/entdecken_erleben/sehenswuerdigkeiten/schloesser-und-ruinen/ruine-froburg-trimbach)
