This large, circular tomb is the final resting place of the first emperor of Rome.

A park in a small Pennsylvania town is home to an original sculpture by one of its native sons, legendary artist and activist Keith Haring.

A piece of the iconic wall found an unlikely new home in a Vegas bathroom.

This ruined fort and statue are a testament to the last king of Kaua‘i’s savvy diplomacy skills, which briefly brought Russians to Hawai‘i.

An abandoned monastery sits on a far-off island in the Adriatic Sea.

The tallest bridge in California was constructed for a project that was eventually cancelled.

This tranquil park with a spiral viewing tower is an off-the-beaten-path area where renowned people have planted a small grove of trees.

A train tunnel that was made obsolete by the dam it helped create.

Macabre astrological automaton clock dating to the late 1400s.

The world's only complete colossal squid specimen is on display at the Te Papa Museum.

This geothermal hot spring hides beneath a slowly growing mineral dome.

A double cantilever system bridge that was designed to prevent flood damage.

A southern Swedish island is home to the last ERSTA artillery battery, meant to protect the shoreline during the Cold War.

A giant owl named Rocco oversees mythical woodland creatures along these charming mountain trails.

This suburban park recalls the history of a famous tavern. Despite the name, it's no ordinary place!

An enormous Soviet aircraft, the only one of its kind, stands at the deserted shore of the Caspian Sea.

Bioluminescence in the reefs of the Maldives causes the sea to glow like a starry night sky.

A relic of the Cold War in Chicago.

The last vessel built by a submarine pioneer stands as a monument to his legacy.

A castle perched precariously over the Crimean Sea.

An exquisite tunnel of cascading flowers.

A magically clear, blue river that seems to spring from nowhere.

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

The oldest natural aquarium in the United Kingdom.