Where Stoddart and Connolly suffered in the infamous Bug Pit.

This "tower of death" has acted as an observatory, a religious hub, and an executioner's lair.

An incredible mosaic-lined monument said to have held the remains of an ancient Roman empress.

This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.

Italian poet Dante Alighieri is entombed in this small mausoleum in Ravenna, and his hometown of Florence has never been too happy about it.

The Avenue of Mausolea is a series of grand palatial tombs.

Royals, rebels, and artists have all conversed at this grand 19th-century Viennese coffee house.

For more than 170 years, this family-run bakery has been serving Berlin’s best Baumkuchen, or “tree cake.”

A silly medieval mural preserved on the side of a Viennese house.

Dine amidst exotic plants at this former royal greenhouse.

Witness traditional silk production in the Uzbek city that's been a hub of sericulture for over a thousand years.

An exquisite Baroque church in Vienna's old town.

The solemn exterior conceals an opulent interior of this 17th century church.

The former private quarters and office of Dr. Sigmund Freud now hosts a museum housing the works of the founding father of psychoanalysis.

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

The unique collection of gifts includes braids of human hair, a spoon, and a Virgin made of bread.

The famous artist couple lived and worked here, in two different houses connected by a bridge.

Frida Kahlo's childhood home, now a museum of her life and works.

The unique collection often goes unnoticed by visitors focused only on the archaeological objects.

It's believed this golden brick is part of the legendary lost Aztec treasure.

This colossal ancient jaguar sculpture was used as a vessel for the hearts torn from sacrificial victims.

Psychedelic murals coat the inside of a nondescript research library.

The ruins of an ancient temple to the Aztec wind god discovered in the middle of a metro station.

Once home to an aristocratic family and a workers' organization, this intricately tiled building now houses a chain restaurant.