There's a mini version of Iguazu Falls hidden in the Balkans, and it's got a rope swing.

1513 Turkish world map, full of European state secrets and snarky commentary.

Ancient serpentine sacrifice holder that has stood the test of time.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

A curious cave church carved into the face of a cliff.

Gargoyle head that brings good luck.

An ancient knight and a symbol of the city's freedom.

Bridge that died in war and was resurected.

This top-secret nuclear bunker hidden in a Bosnian mountain has been converted to a modern art exhibition space.

This museum preserves the hand-dug tunnel that kept Sarajevo afloat during the Serbian siege.

A number of craters left by fatal mortar strikes have been filled with red resin to remember those lost during the Siege of Sarajevo.

Oriental bazaar in the heart of Sarajevo.

The place where World War I began.

A war-torn Olympic relic is being overtaken by graffiti and nature.

These warring psychedelic crags commemorate an unsuccessful military operation.

The fossilized remains of ancient California redwoods.

California's own medieval Italian castle, authentic down to the 300-year-old iron maiden in the dungeon.

Concrete strongholds stand guard over the Golden Gate.

Guns that have been defending San Francisco since 1904.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

A masterpiece in Golden Gate Park by virtue of the artist’s debt.

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

Alleyway plaque commemorating the death of a fictional character in The Maltese Falcon, not far from the author's home.