Head underground and take a tour of the city's working sewer system, and see the underground river Senne, which defined Brussels for centuries before being covered in the 19th century.

Only museum in the world devoted to bookbinding and book arts holds a permanent collection representing five centuries.

Most prolific publishing house in the 1600s open to the public.

A once-magnificent collegiate church is falling into ruin.

This giant urban staircase was built to keep the city's brave fighting men from getting waylaid in the red light district.

A maze of crosses marks the jumbled divide between the Netherlands and Belgium.

A wonderfully kitsch bookstore the size of a supermarket.

The site where one of the most famous poems of World War I was composed is preserved to honor the legacy of the work.

This Greek temple, open only an hour a day, was the site of a war of tastes between an architect and an artist.

This modern arts center is built around a gem of late-Baroque architecture.

Christ's blood preserved in a Belgian town.

A rare example of World War I trenches from the British front.

A marble Lucifer hides behind the pulpit of this Gothic cathedral.

A magical and peaceful ruined Cistercian abbey in what is now southern Belgium.

Three floors of musical instruments coming from all corners of the world and hundreds of years of musical history.

The Devil’s own choice when he needs a drink in Brussels.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

Each spring, a dreamlike carpet of bluebells overtakes the forest floor.

Plaques on its facade commemorate the Tiber's most destructive deluges.

A deep mark on the remains of a Roman temple, believed to be left by a legendary warrior.

Psychoanalyst Carl Jung reported a paranormal experience after visiting this mosaic-lined Roman baptistry.

An incredible mosaic-lined monument said to have held the remains of an ancient Roman empress.

A fortified medieval basilica on the Caelian Hill preserves extraordinary frescoes and one of Rome's most beautiful hidden cloisters.

This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.