An ancient octagonal weather station named for the eight Greek gods of wind.

This mystical orb covered in strange symbols is thought to have been used in ancient Greek magical rituals.

The railway carts travelers to central Athens's highest peak, which offers stunning vistas of the city.

Hidden in a secluded Greek cove is a pristine beach marred only by the rusting smuggler's hulk stranded on its shores.

This collection of 20th-century toys is filled with a lifelong personal toy collection brought from the U.S. to Amsterdam.

Devious political maneuvering and four ancient, working telescopes are central to the world's second-oldest observatory.

Tucked away in the Leiden city hall are a group of works by famed artist MC Escher.

A former plague hospital turned medical museum.

The house of physicists Paul Ehrenfest was also a temporary dwelling and study for his good friend Albert Einstein.

The remains of a medieval wall discovered in the basement of a jewelry store.

Once the world's biggest telescope, it was later used as a coat hanger by a famous Dutch astronomer.

Graffiti covers the walls of a room where university students through the centuries have waited nervously to defend their theses.

Unknown to many, this is where items not displayed in a Dutch history of science museum are held.

A monument to the 16th-century mathemetician who dedicated his life to calculating the numerical value of pi.

The world's first transgenic bovine has been preserved at the museum where he spent his final years—though his old stable is now a cafe.

A plaque hidden in the law faculty at Leiden University honors the first scientist to make liquid helium.

Only a few walls remain of the last church the Pilgrims used before they sailed to North America.

This century-old street sign is a forgotten remnant of the old city.

The remnants of a WWI naval mine that once terrorized the country now decorates a street.

A relic of the old jail still stands in its original location.

A massive explosion that leveled hundreds of buildings in the city of Leiden is remembered by a waterside plaque.

A retail shop has preserved the 17th-century food cellar from the old building it now occupies.

One of the great math minds of the 17th century is underfoot in this 900 year old Dutch church.

Albert Einstein would often sit in this chair during visits to the observatory to discuss science with Willem de Sitter.