This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

Medicinal spa created from the mineral-rich runoff of a geothermal power plant

A striking symbol of the Bulgarian capital.

This memorial to the victims of the Romanian Revolution of 1989 is often compared to a potato on a skewer.

Romania's triumphal arch looks out over Bucharest.

The European towns of Brașov and Râșnov each have proud signs reminiscent of the Hollywood sign.

A fire once nearly devoured this gorgeous 14th-century Gothic cathedral.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

The bust of Romania’s most notorious ruler, Vlad Dracula aka "Vlad the Impaler," keeps watch over the ruins of his medieval court.

This once-derelict building is now one of the most beautiful bookstores in the world.

This elaborately decorated, fairytale-like Romanian royal palace is one of the most striking castles in Europe.

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

Roman ruins top white travertine terraces formed by ancient hot springs.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

This curious fresh and salt water lake holds a secret that draws in deep divers from around the world.

Order your coffee crowned with salted whipped cream or blended with coconut and ice.

The notorious "Hanoi Hilton" where Vietnamese colonial subjects and later American POWs, including John McCain, were imprisoned.

Striking, enormous gold-plated sculpture of Buddha installed in the 19th century.

This sensational silver temple is the product of centuries of metalworking.

One of Ayutthaya’s most iconic locations is a mysterious, hauntingly surreal miracle.

An enormous Buddha peers through a gap in its ruined chamber.

This bridge made famous in a novel and on-screen wasn't actually built over the river Kwai.