These former Nazi anti-aircraft towers offer a singular view of the north of Berlin in the summer, and a sanctuary for bats in winter.

In the days before house numbers, these colorful signs held clues about various buildings' purposes.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

These flying foxes dangle from the trees around the library like fuzzy black fruit.

A giant floating rubber duck-bunny painted with a different design every year.

For decades, Puerta del Sol has been illuminated by a giant, guitar-wielding bottle of sherry.

An enormous Polaroid picture adds an artistic flair to Rotterdam.

One of the most spectacular bridges in Spain spans a narrow chasm that divides the city of Ronda.

This abandoned viewing platform has become a monument to unnecessary government spending.

Reminders of the Battle of Berlin still scar the railway.

The skeletal frame of a decommissioned gas-pumping station offers breathtaking views of greater Berlin.

A detailed pachyderm supports Rome's smallest Egyptian obelisk.

Vietnam's largest Buddha statue depicts a female sage.

This roadside monument commemorates the huge weapon built by an Ethiopian emperor's hostages.

An early 19th-century English style garden hidden in the Rotterdam cityscape.

A strangely curved lamppost stands tall over this avenue in Rotterdam.

This charming pup is meant to celebrate the youth and stubbornness of the city's students.

A small island dotted with old, historic Finnish buildings.

The tangled roots of a giant banyan tree have fully reclaimed the ruins of this abandoned warehouse.

This iconic 1958 tower welcomes air travelers to Tucson with neon-lit letters and architectural style.

This painted Lego bridge is the product of over a century of locomotive history.

Two cannon-like cranes were installed on top of the bank building to fend off bad feng shui.

The Netherlands' first car tunnel has an unusually rectangular shape.

In the summer, the area around this sculpture transforms into a vibrant concert venue.