Large, airy hallways hide within an impenetrable fortress that beckons urban explorers.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

A marvel of Byzantine engineering under the streets of Istanbul.

Roman ruins top white travertine terraces formed by ancient hot springs.

A colossal floating restaurant built to look like a ancient Chinese imperial palace.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

Across the Pacific in a raft, a museum dedicated to Thor Heyerdahl's now legendary expedition.

One man's exploration of the human form, including the bizarre and delightful "Man Attacked by Babies."

The convergence of two currents makes this a surprisingly pleasant getaway in the Arctic Circle.

One of the largest Buddhist stupas in the world keeps an eye out in every direction.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

Copenhagen's celebrated theme park and gardens.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

Réunion Island's highest point is a two-million-year-old volcano and a paraglider's paradise.

A British general, a suggestive tree, a map of paradise.

This small group of sand dunes manages to pack in a strange rainbow of colors.

Construction of Barcelona’s iconic (but controversial) church was finally completed in 2026—a century after the death of its architect.

An old Dutch lightvessel is now stuck in a dock near the mouth of the Suriname River.

This futuristic building is yet another architectural wonder in Dubai.

A preposterously luxurious hotel with gold-plated iPads, Rolls Royce chauffeurs, and a staff that trains by watching "Downton Abbey."

Whitewashed mosque contains the world's largest carpet.

Museum celebrating the ocean, with the largest wunderkammer dedicated to sea exploration.

This subterranean necropolis holds three floors of antler-dug grave caves.