Gerolstein information
The coat of arms of the town of Gerolstein, with information about the foundation of the town by the Blankenheims.
A map of western Germany, showing Gerolstein and Blankenheim.
The homepage for the town of Gerolstein, in German.
Gerolstein seems to be a variation of the name and location Gerhardstein, taken from Gerhard von Blankenheim. Especially check the links to "About the Name" and "Burg Gerhardstein."