This once-grandiose behemoth of a monument from the socialist era now sits quiet and closed up.

The site of many battles and tragedies, including the 40 maidens who leapt into the sea.

A spectacular Bulgarian cave resembling a devil's head with a waterfall rushing down its throat.

A striking symbol of the Bulgarian capital.

This tiny Bulgarian town offers a stunning location in the mountains and a storied history.

The ceiling of Prohodna Cave in northern Bulgaria affords a peek at the sky via two deity-sized-eye-shaped holes.

This historic black and white monastery is one of Bulgaria's architectural jewels.

An abandoned saucer-shaped monument in the Bulgarian mountains.

An architectural marvel that spans the Arda River, and has stories of a haunted past.

Bizarrely shaped rock formations in northwest Bulgaria come with equally bizarre legends.

This massive concrete sculpture is said to be the heaviest communist monument on Earth.

Inside this medieval church resides a unique set of murals.

Walk along the medieval fortifications that have been protecting Tallinn since the 14th century.

One of the oldest lighthouses in the world has been in continuous use since it was first built in 1531.

For the last century, this international border within a small town has appeared and disappeared various times.

Wars fought and wars won are remembered by these abandoned bunker ruins.

Historic slum of Tartu.

The widest natural waterfall in Estonia is a sight to see in all seasons.

A wooden replica of France's famous tower.

The Guardian of Tallinn.

The labyrinthine home of the National Archives of Estonia is an experimental blend of architecture, art, and history.

This small Estonian hill is covered in hand-made twig crosses that are said to bring good luck.

A decommissioned submarine base makes a great space for graffiti art.

Rusted cars, trucks, and buses form a fascinating collection of Soviet-era machinery.