Some 380 million years ago a subtropical sea covered the area creating a mighty fossil reef, which is today known as Gerolsteiner Dolomites.
Several hiking trails lead along geological as well as historical features presenting an ocean-less reef, ancient lava flows, an ice age cave, crater lakes, and a tamed cold water geyser.
There will also be some Roman and some medieval content, as well as some wildlife.
A reef without an an ocean
In more recent times (30,000 years ago) volcanic activities shaped the landscape we see today.
Kasselburg, a 12th century castle
Villa Rustica Sarabodis