Humble beginnings for one of the world's most famous scientists.

This huge metal monument is slowly being stripped to its concrete skeleton.

Large, airy hallways hide within an impenetrable fortress that beckons urban explorers.

This stunning, out-of-the-way Croatian monument commemorates a community's uprising against occupying fascist forces.

Where the lovelorn find a home for their sentimental keepsakes.

A musical instrument played by the sea.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

Different sections of the Zemun Fortress were built in the 14th and 15th century as a response to the advance of the Ottoman Empire.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

Oriental bazaar in the heart of Sarajevo.

Inat Kuća, or "House of Spite," is more than just an oddly named restaurant.

A number of craters left by fatal mortar strikes have been filled with red resin to remember those lost during the Siege of Sarajevo.

The place where World War I began.

Op-art architecture designed for happiness.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

Over time, this castle grew to encompass the entire island.

The reconstruction of this prominent building fulfilled a long-written command.

A black cat protests the City Guild in Riga's Old Town.

The oldest housing complex in Riga is a mini timeline of architectural trends.

3,000 market stands in five former Zeppelin hangars.

The Guardian of Tallinn.

This soviet pilot's graveyard is filled with headstones made of airplane fins.

A subterranean house of worship carved right out of the bedrock.

This floating sculpture of ice is a poignant reminder of nature's power.