Rich with fauna and flora, nature-lovers can walk across the sea at this UNESCO World Heritage spot.

The place where Czar Peter I of Russia resided in 1697 during his Grand Embassy.

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

A line number in Amsterdam that will likely never be used again due to its tragic history.

A unique work of automotive art calls this shopping center home.

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

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

Colorful and chaotic stacked hotel in North Holland.

A beautifully eclectic mix of architectural styles.

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

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

The ruins of an 800-year-old monastery boasts the tallest round tower in Ireland.

400 million years of erosion shaped these fascinating seaside caves, which made an appearance on 'Game of Thrones.'

These narrow stone granaries have been used to store and dry out grain for hundreds of years.

A cluster of granite granaries perched on stilts.

In Spain, the ruins of a Roman military camp sit along a flooded section of a river.

This watchtower once presided over the Berlin Wall.

For patriotic Russians, this memorial honoring the Soviet soldiers who died liberating Berlin in 1945 is the most sacred location outside of Russia.

This sprawling Jewish cemetery is one of the largest in Europe.

These engineering masterpieces are a dominant feature of the Belfast skyline.

These murals stand as reminders to the troubled history of this Northern Ireland city.

It was once nicknamed "the most bombed hotel in Europe."

These barriers stand as stark reminders of Northern Ireland's troubled past.

It is said a heartbroken man visited the gap every day to stare blankly out at the sea.