Trier- Basilica of Constantine- Organ

Constructed around AD 310 as Constantine’s throne room, the brick-built basilica is now an austere Protestant church. With built-to-impress dimensions (some 67m long, 27m wide and 33m high), it's the largest single-room Roman structure still in existence. Its organ, with 87 registers and 6500 pipes, generates a seven-fold echo.