A preserved oak tree about 3,500 years old found in Riga, Latvia.

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

Romania's triumphal arch looks out over Bucharest.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

3,000 market stands in five former Zeppelin hangars.

This charming Latvian lane doubled as Baker Street on the Soviet Union’s version of Sherlock Holmes.

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

A former Latvian headquarters of the brutal KGB secret police is now open as a grim reminder of their atrocities.

An eerie, derelict amusement park in Berlin.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”