The church was the site of the 843 Treaty of Verdun negotiations, which partitioned Charlemagne's empire.
It was elevated to a Minor Basilica in 1928, the first in the Rhineland.
The interior holds the sarcophagus of St. Castor, a 4th-century hermit and missionary.
The church features a distinctive layout with four towers, a feature common in Rhenish Romanesque architecture.
The Basilica serves as a parish church for the Roman Catholic Church in Koblenz.
The Basilica of St. Castor is the oldest church in Koblenz, originating from the 9th century. It stands as a significant example of Romanesque architecture, characterized by its twin-towered west facade and four-tower design. The basilica is historically notable for being the site of the 843 Treaty of Verdun negotiations, which laid the foundations for the later division of the Frankish Empire. The interior contains the sarcophagus of St. Castor of Karden, whose relics were transferred here in 836. Extensive reconstructions occurred during the 12th century, shaping its current limestone appearance. The church was elevated to the status of a minor basilica by Pope Pius XI in 1928. It suffered significant damage during World War II and underwent subsequent restoration. The interior highlights include the high altar with 15th-century paintings and various tomb monuments of the Trier electors.
The grassy square in front of the west facade offers the best perspective of the twin towers.
Walk around the exterior to view the detailed stone carvings on the cornices and column capitals.
Visit the adjacent St. Castor Garden for a view of the church's exterior architecture.
Check for local organ concerts, as the basilica is known for its acoustic properties.
Do not enter during ongoing liturgical services if you are not there to worship.
Occasionally closed to tourists during private ceremonies or specific religious holidays; check the parish bulletin board.
Maintain a quiet, respectful demeanor; shoulders and knees should be covered as a sign of respect.
