Lyon, France is home to two remarkably preserved Roman theaters, one dating back to 15 BCE.

This abandoned church in central Lyon is missing its front stairs.

Lyon's "Wall of the Silk Weavers" is one of the largest murals in Europe.

Lyon's miniature version of the Eiffel Tower was built as a statement in support of French secularism.

This hidden garden boasts amazing views of Lyon.

A colorful piece of contemporary art cheerfully clashes with Lyon's historical architecture.

Seven mini rowhouses fill the gap between 54 and 70 Westerstraat.

The last of Amsterdam's original sea level markers remaining in place.

Amsterdam's narrowest house facade is a monument to 17th-century tax evasion.

A floating cat sanctuary on an Amsterdam canal.

The former headquarters of history's oldest megacorporation.

One of Amsterdam's narrowest houses is located right across the canal from its widest.

The former home of a mad diplomat is said to still be marked in bloody, arcane scrawls.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

This unattributed sculpture in Amsterdam is hiding in plain sight.

This plaque marks the former home of one of the first women physicians in the Netherlands.

A set of seven houses, each built in a style that represents a European country.

Only a few walls remain of the last church the Pilgrims used before they sailed to North America.

Some 80,000 Delft Blue tiles line the inside of this Amsterdam walkway.

This statue of the great Argentinian car driver is located near a famous curve of the Monaco Grand Prix.

This mountain trail inspired Nietzsche to complete his magnum opus.

The construction of a tram line unveiled hidden remnants of the old medieval city.

This massive blockhead sculpture hides an entire library.

An Orthodox church built by the Royal Family for the Russian community exiled to the French Riviera.