The remarkably well-preserved final resting place of a powerful ancient Thracian king.

A magnificent, glittering building tucked into a tiny Bulgarian mountain town.

A Bulgarian monument to Russia's role in World War II is constantly being painted in pop culture protest.

An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

A tidal bore with its own festival.

Eurasia's most difficult place to hang out, and farthest point from sea access.

Where the Great Wall of China meets the sea.

The tallest stationary dunes on Earth also happen to sing.

These layered sandstone mountains in China look like they are made of pressed crayons.

For those with no fear of heights: a skywalk 4,700 feet up on a Chinese mountain.

Intensely colorful calcite pools in Southern China.

A total of 999 stairs lead visitors through a massive hole in a mountain known as the Gateway to Heaven.

One of the world's largest ice festivals dazzles visitors for over a month with radiant sculptures and carvings.

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

A bronze kitty adorns the grave of the polar explorer who brought the original feline to the Antarctic.

A curious little museum dedicated to the furry feline in the cat haven that is Old Town Kotor.

This house's itty bitty size means no humans allowed.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

The statue honors an adventurous seafaring cat.

Built over an abandoned train yard, this hidden gem is full of winding paths and offers gorgeous views of Sydney Harbour.

The first, and perhaps only, monument dedicated to Wikipedia.

This antique thermometer honors the creator of the first universal temperature scale.

Poland's oldest salt mine has nearly everything one needs to live underground forever.