Prehistoric animals decorate this popular outdoor park.

A collection of colorful dinosaurs hidden in an actual rainforest.

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

Try not to get slimed in Tribeca.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

Street artists transformed an abandoned air vent into the beloved Star Wars robot.

Cryptic messages embedded in the New York City sidewalk.

Bouncing, delightful, mechanical art at the MIT Museum.

A tiny monument to the classic American candy.

This boulder with a 200-word legal dedication to God has remained hidden in the woods for over 150 years.

A Milanese café entirely designed by the American director Wes Anderson.

Site of a famous 19th-century transcendentalist utopian community, now abandoned.

This little-known rival to the Library of Congress houses one of the largest collections of pre-1876 American books, newspapers, and manuscripts.

The names Lúthien and Beren can be found inscribed on the shared grave of the famous writer and his beloved wife and muse.

A complicated, forgotten beacon of hope for thousands of immigrants, "Canada's Emerald Isle" lies in ruin.

A small island less than half a mile from Venice is a forbidden island with a dark and twisted past.

A 6th-century stone lies at the site of the mythical battle waged between King Arthur and his nemesis Mordred.

Hidden beneath the streets of London is a secret subway that only carried mail.

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

A collection of housewares from recent Irish history adjoined by a tower from ancient Irish history.

This Irish show cave is said to have been the site of a Viking massacre that claimed 1,000 lives.

The oldest inn in Kilkenny was established by the first convicted witch in Ireland.

A standing relief of a Norman knight whose posture marks him as a Crusader.

This ancient Irish religious site is covered in ancient carvings, many of which have barely aged.