Bad Nauheim's local mountain is 268 m above sea level. Due to its outstanding location, Johannisberg was a place of worship for pagan, Celtic and Germanic customs long before Christianity. Finds prove a settlement already in the stone and bronze age. A mission church is said to have been built here as early as 779. As a baptismal and mother church, the Johanniskirche became the original parish of the entire northern Wetterau. During the Reformation, however, the church was abandoned and quickly decayed. Only the church tower remained in its foundation walls and was converted into an observation tower in 1866. Since 1965, the tower has housed the public observatory.
Only a few steps away from the public observatory you will find the remains of a Roman signal tower from the 2nd century, which is part of the UNESCO World Heritage Limes. It is the best preserved signal tower along the Limes.
It is thanks to the efforts of the Freundeskreis Weinanbau Johannisberg that after 100 years vines are growing again on Johannisberg. At the end of the 19th century the "Johannisberger", the wine of the Bad Nauheim wingerts, was known as a good wine. In the vernacular the sunny slope is also called the "Nizza". Wine is said to have been cultivated here more than 600 years ago. Around 1900 the vines disappeared, because the town as owner lost interest in the labour-intensive winegrowing. The red roof of the Café Restaurant Johannisberg is visible from afar from the town. This traditional restaurant was already appreciated by Empress Sisi, who ate lunch here every day during her stay at the spa.