A treasure trove of scientific instruments from the 17th and 18th centuries.

This stone in Lake Geneva was once the reference point used to determine altitude in Switzerland.

Dynastic Home of the De Piro Family.

The floor of this spectacular Baroque sanctuary is covered in memento mori.

Malta’s largest cemetery is a Victorian-era architectural masterpiece.

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

Burial grounds for more than 1,000 bodies deep under the modern town of Rabat.

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

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

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

These semi-natural waterfalls hint at the park's Victorian-era industrial past.

The beautiful baroque library of the Hapsburg empire.

Designed as a reminder of one of the darkest moments in Austrian history.

A magnificent collection of imperial armor and weaponry.

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

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

Balanced on four stone pillars, this historic tower was the site of a tragic political assassination.

The sacred shrine of the Yazidis.

This beautiful arched gate is all that remains of the fortress the ancient mountaintop town of Amadiya once was.

A bloody history is captured in this former prison turned museum.

An ancient fortified mound raised over the millennia from settlements built one on top of the other.

At the heart of an otherwise bustling city lies some oddly abandoned and ignored historical ruins.