Top 12 Castles around Nieder-Olm

The citadel is, next to the cathedral, the most important historical building in Mainz. First fortified in 1620, the citadel took its present form on Jakobsberg hill in 1660. The citadel and its surroundings document Mainz's military history in a very small area: from the Roman war memorial "Drususstein" to the barracks buildings from the time of the Federal Fortress in the 19th century, and finally to the air-raid shelters from the Second World War. The Drusus Bastion, with its mysterious passageways, is particularly captivating. Source: http://www.festung-mainz.de/zitadelle/einfuehrung.html

The grounds of the Mainz Citadel are open year-round. The two gates to the citadel (the Commandant's Building and the bridge at Windmill Hill) are no longer closed. The citadel can therefore be visited even late in the evening. Access may be restricted only for a few specific events (such as Open Ohr). Source: http://www.festung-mainz.de/zitadelle/touristische-hinweise.html

After World War II, the French occupying forces confiscated the complex (until 1955). In the 1960s, the Mainz Commercial Vocational School was located in the citadel until its relocation to a new building on the Hartenberg. Today, the citadel belongs to the city of Mainz and houses numerous municipal offices. The Mainz Citadel has been a listed historical monument since 1907. The moat in the southern part of the citadel has been a protected landscape since the mid-1980s as an "anthropogenic biotope" of "national importance."[3] The City History Museum is now housed in Building D in front of the Drusus Stone. The citadel and its surroundings document Mainz's urban history in a very small area: from the Roman war memorial Drusus Stone to the barracks buildings from the federal fortress era in the 19th century, and on to the air-raid shelters from World War II. Since 1975, the OpenOhr Festival, a themed youth culture festival with discussion forums and workshops, cabaret, and live concerts, has taken place annually at the Mainz Citadel over the Pentecost weekend. In October 2015, the Mainz Citadel was awarded the Hague Plaque by UNESCO, designating the structure as a protected monument. In the event of damage caused by armed conflict, the International Court of Justice would assume prosecution should the German government be unable to do so.

https://www.zitadelle-mainz.de Construction of the fortified citadel began in 1620.

The keep has been preserved and can be climbed. The upper (narrow) section is a bit dark, but the climb is worth it!

The citadel was expanded from 1655 onwards as an addition to the city's fortifications. From up here on Jakobsberg hill, there is also a beautiful panoramic view over Mainz as far as the Taunus mountains.

The customs tower was built around the year 1000 as a pass barrier on the road between Mainz and Bad Kreuznach! The name goes back to a legend of Saint Ursula of Cologne! On her way back from a pilgrimage to Rome, she crossed the Selz here with her entourage of 11,000 virgins. In the hope that another 11,000 virgins would follow the same path, the Schnorressänger from Elsheim took over the sponsorship in 2006.

Definition of a citadel ("small town"): A citadel is a small, self-contained fortress, either located within a larger one or forming part of the enceinte (main line of fortifications) of the larger fortress. In the event of an enemy storming of the city, it served as a refuge for the garrison and the city's last line of defense. The citadel and its surroundings document Mainz's urban history in a very small area: from the Roman memorial Drususstein to the barracks buildings from the 19th-century period of the Federal Fortress, and on to the air-raid shelters from the Second World War. In October 2015, the Mainz Citadel received the Hague Plaque from UNESCO, which designates the structure as a protected monument.