St. Gereon's Basilica

Overview

St. Gereon's Basilica features one of the most unusual domes in medieval architecture — a decagonal (ten-sided) structure completed in 1227 that was the largest free-standing dome north of the Alps until modern times.

Highlights

• Decagonal Dome: 16.9 meters in diameter and 34 meters high, an extraordinary Gothic engineering feat.
• Late-Roman Core: The oval nave dates to the 4th century, built as a martyrium for Roman soldiers.
• Medieval Frescoes: Fragments of Romanesque painting survive in the crypt area.

History

Built over a late-Roman cemetery church honoring St. Gereon and fellow martyrs of the Theban Legion. The decagonal extension was added in the 13th century. Severely damaged in 1944, it was rebuilt by 1985.

Visitor Tips

• Look up upon entering to appreciate the dome's ribbed vaulting.
• Combine with a visit to nearby Mediapark or the inner-city Ring boulevard.
• Duration: 20–30 minutes.