Peeking out from Mainz-Oberstadt, these pointed stone walls whisper tales of a bygone era. Welcome to Fort Joseph. This fort was once a key part of Mainz’s baroque fortifications. Fort Joseph, or Josephsschanze as it was also called, helped protect the city. Picture Mainz in the early 18th century. Lothar Franz von Schönborn, the Prince-Elector, commissioned this fort. He wanted to protect Mainz’s interests along the Rhine.
Johann Maximilian von Welsch, a master fortress builder, designed Fort Joseph. Construction spanned from 1713 to 1730. Fort Joseph was part of a second ring of fortifications around Mainz. The upgrade was needed because cannons had become so powerful. Enemies could shoot over the existing Schönborn bastions. Fort Joseph and four other forts were built to relieve pressure on the old bastions.
The location of Fort Joseph was strategic. It stood on the Linsenberg heights, near the Roman aqueduct. This placement allowed it to command the Bingerstraße and Dalheimer Grund. Fort Joseph had two lunettes in front of it. It could control the entire area up to Zahlbach.
Other forts, like Fort Karl and Fort Elisabeth, were connected to Fort Joseph. Crenelated walls linked these forts. The double tenaille system connected Forts Elisabeth and Joseph. This system included ravelins for extra defense. Fort Joseph itself had a blockhouse for retreat cover. It also featured a large open area to defend the “holy valley.” This valley had been used for burials since Roman times.
Let’s descend below the surface. Underneath the Czerny-Weg lie the remains of Fort Joseph’s ditch. The escarpment, the side of the ditch facing the fort, still exists. The opposite side, the counterscarp, is gone now. But an underground passage remains: the counterscarp gallery. From this gallery, defenders could fire upon enemies in the ditch. You can still see the embrasures and powder vents inside. These vents helped to clear gunpowder smoke. The gallery was built in open air and then covered with earth.
Originally, the counterscarp gallery connected to Fort Joseph’s casemates. But this connection was cut off in 1944. A bomb shelter was built, blocking the passage with a sanitary installation. From the counterscarp gallery, smaller mining tunnels branch towards Zahlbach. These tunnels, about 65 meters long, held explosives. They would be used to stop approaching enemies.
Unfortunately, this massive fortress strained the state’s finances. The “Engineer Command” responsible for Mainz’s fortifications complained about neglect. Rudolf Eickemeyer warned the Prince-Elector about the deteriorating state of the defenses. In 1792, French Revolutionary troops approached Mainz. The city was lost to France again.
One more thing: In 1934, the Nazis erected a monument here. It honored the fallen soldiers of Foot Artillery Regiment No. 3. You can still see the stone cannon and Prussian eagle. The eagle holds a sword and a bundle of lightning bolts.
Today, the remains of Fort Joseph are a cultural monument. Though time and war have taken their toll, the spirit of Fort Joseph endures. Its stones stand as a testament to Mainz’s strategic importance. They speak of battles fought and defended.