An 11th-century medieval castle cascades over the town of Numão.

In addition to showing films, this one-screen arthouse cinema from the late 1940s is a museum of old film equipment.

This oddly shaped church resembles a rocket.

This glass skywalk offers vertiginous views down the volcanic cliffs to the beach below.

Europe's oldest still-operational tea farm also boasts a spectacular view.

This little-known national museum houses over 40,000 works of art from across the world.

One of the largest Roman settlements in Portugal.

Once a year, local students "clean" this statue with a champagne shower.

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

Troublesome students were detained in this tiny graffiti-covered university jail.

First point in the Struve Geodetic Arc, a 19th century undertaking to measure the Earth's size and shape.

A historic scientific breakthrough that crosses nine borders.

Historic slum of Tartu.

The labyrinthine home of the National Archives of Estonia is an experimental blend of architecture, art, and history.

The secret cells in the basement of the KGB's Estonian "Grey House" have been preserved as a grim Cold War museum.

Hundreds of signs pointing to the birthplaces of current Helsinki residents form stalactites on the ceiling of the cave-like Kamppi metro station.

Dedicated to the outnumbered Finnish forces who pushed back Soviet forces during the conflict.

One of the oldest structures in Helsinki is this burrow grave that dates back to the Bronze Age.

Atop this electronic store resides a massive fighter jet.

This church also serves as a lighthouse complete with a beacon.

This former hospital was once one of the oldest mental health facilities in Europe.

The door to the museum holds a unique artifact from the Finnish Civil War.

These enormous, stern-faced statues greet visitors with lanterns, and sometimes costumes.

In the waters outside Helsinki, a tiny island once used as a military outpost now welcomes visitors.