The pretty iron lamp is a reminder of the architecture underneath London's streets.

Michael Jackson got Bad and Crocodile Dundee walked on heads in this iconic Brooklyn subway station.

Walking around West Harlem reveals a scavenger hunt of beautiful bird murals.

Red frames showcase remnants of one of New York's original subway stations.

Commemorating the spot where the famous scientist fed his pigeons.

Detailed facade of a brownstone in Boerum Hill.

A terrific purveyor of natural history objects and curios.

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

A star-shaped fortress town fort built in the geometric model of the Renaissance utopian city.

Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

Two very green residential towers cleaning the air in one of Europe's most polluted cities.

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

Carvings in Turkey's Marble Road may have directed ancient Romans to a hidden brothel.

This Communist-era residential block is one of the longest residential building in Europe.

Surreal works of unreal stone and metal dot the landscape of this Latvian art park.

The mile-long pier stretches from a ruined fortress out into the Baltic.

This impressively complicated radioastronomy research center was once a tool of Soviet spies.

These abandoned vessels are destined to be reclaimed by the forest.

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

This Estonian watchtower looks like a big tree with two giant bird nests on it, complete with a "golden egg."

The enormous isokinetic structure hangs within a science center in Estonia.

A former imperial sea-fortress and Soviet prison.