Where the lovelorn find a home for their sentimental keepsakes.

This whimsical fountain pays tribute to Toronto's four-legged friends.

Christianity and Islam have clashed, yet here a Serbian Orthodox church and a mosque stand together.

The only Roman honorific column in Istanbul.

Taking the subway here means doing so over a bridge located in the middle of an estuary.

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

The most metal church of all time was built in record time because of an international, pious pissing contest.

This crucial gathering spot along the "hippie trail" still displays old notes between traveling beatniks and backpackers.

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

1513 Turkish world map, full of European state secrets and snarky commentary.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

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

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

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

A marvel of Byzantine engineering under the streets of Istanbul.

With over 10,000 lights, this engineering marvel lights up the city after dark.

The charmingly disheveled clock tower of Tbilisi's puppet theater.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

Breathtaking and huge 430 year old maps of Italy.

These ancient artifacts are a testament to the enduring significance of the bull in Spanish culture.

This enigmatic artifact is a rare depiction of an ancient Iberian noblewoman.

One of Madrid's oldest trees, with a long and colorful history, resides in El Retiro Park.

This funky former tobacco factory is one of the most striking examples of Madrid's cultural diversity.