Underneath this Byzantinian church lies a necropolis filled with ancient tombs and the ruins of previous churches.

A collection of art from Bulgaria's time as a communist state.

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

A sixth-century Byzantine cistern hidden below a modern carpet store.

An Art Nouveau gem hides beneath the layers of city grime obscuring this once-magnificent building.

A meow-velous tribute to a beloved street cat, made famous on the internet.

A tiny park in the middle of some big power politics.

Have tea in a cemetery with a dazzling view of Istanbul.

This shuttered power plant is now Turkey's first industrial archaeology museum.

Quite possibly the oldest love poem known to humankind.

This half-forgotten fortress was constructed by the Ottoman conqueror of Constantinople.

Large miniature theme park with 100-plus models.

Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

This museum was invented in a novel before being made real by the author.

A gorgeous, Gaudí-esque stairway constructed in the city of Istanbul by a prominent Jewish family.

Legend says if you stick your thumb in the hole and it gets wet, your wish will be granted.

A small etching on the white marble parapet was written in runic script by a Viking mercenary.

The ornate miniature mansions were built for Istanbul's feathered residents.

An ancient Thracian city where fire rituals were practiced on the largest cult altar in Southeast Europe.

A tribute to smugglers and the Butter Wars.

Not many houses move across borders, this one did it twice.

Intricate metal sculpture that's half gothic cathedral, half construction equipment.

A piece of stonework relief commemorates the site where the Devil's rage, and odd apparel, destroyed a house.

This residence straddles a border between Belgium and the Netherlands.