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

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

The medieval home is still engraved with the symbol of the profession, an eye flanked by two axes.

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

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.

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

Unconventional site where the tracks of Zurich tramcars intersect.

The Swiss hilltop housed an early 20th-century vegetarian nudist colony.

Video games, body language, and postal history are all on display in this Swiss museum.

The bears of Bern have been a city highlight for over 500 years.

The world's longest and deepest train tunnel.

Natural history museum displaying a famous taxidermied St. Bernard.

A cablecar-station-turned-revolving restaurant with 360-degree views of the Swiss skyline.

This long line of cement defensive wedges is named after the famous chocolate bar for obvious reasons.

The last woman executed for witchcraft in Europe is remembered in this Swiss museum.

A Swiss board game museum housed inside a picture-perfect castle.

Over 3km of caverns and caves at the Switzerland-France border contain the largest underground river in Central Europe.

This simple apartment may have inspired some of the most important theories in the history of science.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

A breathtaking bridge that crosses a vast gorge over a river's torrents, and has a tale of a devil architect attached.

The alpine falls where Sherlock Holmes apparently met his demise can actually be visited.

This is not only one of the oldest collections in Europe, but also possibly the most beautiful.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.