An ancient iron pillar in Delhi that seems to be rustproof.

Made by a man on a worldwide sanitation crusade.

Time has stopped at the house where Gandhi died.

A startling, centuries-old subterranean marvel hides in plain sight.

This hidden Sufi cemetery is a spiritual monument for India's third gender community.

Worlds' largest inhabited river island.

The mysterious empty cupola behind the monumental arch points to an ancient prophecy of Delhi.

Ancient traditions and surreal birdwatching come into sharp relief along one of the world's most polluted rivers.

This alley in downtown Chicago held the bodies of over 600 people after the fateful Iroquois Theatre fire.

This memorial plaque remembers a strangely shallow maritime disaster known as "Chicago's Titanic."

Where dioramas can follow you home.

Rifle through images of skyscrapers, Worlds Fairs, and more in the largest public postcard repository in America.

The beloved home to all publications indie, erotic, and punky.

The iconic Chicago sculpture hides a beautiful and easily overlooked plaque on the backside.

Years of archaeology, just chillin' by the water cooler.

Nonprofit art center that promotes outsider, intuitive, and self-taught art.

A Bibliophile's Dream.

A tiny theater hidden in an alley plays a constant stream of short silent films for anyone willing to peer through the peephole.

Gold Rush-era tombstones line the park's paths.

Nuclear waste dump site now an environmental sanctuary.

One of few lasting examples of the brief octagon craze that developed into folly.

San Francisco's oldest operating hotel, with a Victorian atmosphere and a "haunted" fourth floor.

An overlooked and unassuming engineering marvel.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.