Roman Watchtower Bad Nauheim

In Roman times, a signal tower was located on the Johannisberg since the 2nd century, which belonged to the system of the Upper Germanic Limes. Structurally, it resembled a Limes watchtower. It probably served to transmit optical signals from the Limes to the Friedberg fort, which had no direct line of sight to the nearest Limes watchtower on the Gaulskopf. Further rear watchtowers of this type existed on the Kapellenberg near Hofheim and near Wölfersheim-Wohnbach. The remains of the Roman signal tower were restored in 2010, and it was also made clear which parts are original and which are additions.

This Roman tower must not be confused with the tower still standing today, the substructure of which dates from around 1300. The octagonal tower in its ground plan belonged to the westwork of the church of a medieval monastery, which goes back to a missionary church said to have been built here in 779. This St. John's Church is considered the baptismal and mother church and original parish of the entire northern Wetterau. The patronage rights to the church were transferred in 1254 by Ulrich II von Münzenberg to the Mainz Cathedral Chapter, which took over the entire monastery in 1310. During the Reformation, the church was abandoned and fell into disrepair. The tower, still preserved in its foundations, was converted into an observation tower in 1866 and has housed the Wetterau Public Observatory since 1965.