Dramatic river bend surrounds a natural red-rocked pedestal.

A peace symbol in Northern Ireland is among the world's largest hedge mazes.

The ancient tomb acts as a calendar that keeps perfect time.

Repository for more than 22 million pickled specimens.

Earth's tallest volcano is sacred to Native Hawaiians, and home to a dozen world-class observatories.

These haunting ruins of a 700-year-old Prehispanic city have witnessed centuries of wars and massacres.

Gilded heaven for philatelists and architecture freaks, still in full working order despite sitting atop tremulous ground.

A jaw-dropping "megalibrary" that turns book-browsing into a geometric adventure.

A quirky and charming restaurant founded by artists.

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

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

A DIY art gallery/music venue/lecture hall dedicated to video game culture.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

Try not to get slimed in Tribeca.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

A trash dump made beautiful by nature's power.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

The fierce beast perches atop a pedestal marking where the historic City of London gates once stood.

On October 17, 1814, a 15-ft. wave of beer ran rampant through the streets of London.

This museum tucked below a charming cafe gives a brief snapshot of photographic history.

A glorious pub known for a spiteful printing feud and its famous typeface lost—then found—at the bottom of the Thames.

The London pub overlooks where the Mayflower was moored before setting sail for the New World.