The attic of a four-century-old canal house hides a clandestine church.

The history and future of cannabis.

The final resting place of soldiers' loyal canine companions.

Largest lake in Great Britain measured by surface area.

The highest peak in the United Kingdom has a history of physics, specters, and a pilgrimage of strange objects.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

Museum dedicated to the terror regimes of Hungary.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

The world's most active stratovolcano is almost always erupting.

Two geological phenomena in one precarious locale: a towering stone window, and a deep blue void.

This prison on the Maltese island of Gozo is almost 500 years old, and they have the graffiti to prove it.

An abandoned set from the 1980 film "Popeye," claimed and repurposed as a theme park by creative locals.

The ruins of a megalithic monument sit right in the garden of a luxurious Maltese resort.

This spectacular dome managed to survive after being bombed in World War II, in an event known as the "Miracle of Mosta."

The Jesus tree of Malta bears a striking resemblance to Christ on the cross.

The remains of a 1st-century aristocratic Roman town house featuring beautiful well-preserved mosaics.

This unique building in the main square stands out among the city's typically Baroque architecture.

Ancient mysterious ruts carved in the bedrock.

This almost-forgotten underground dungeon housed several convicts over the years, including Caravaggio.

This subterranean necropolis holds three floors of antler-dug grave caves.

Stone Age solar temple is aligned with the sun on each equinox and solstice.