This knobby, drooping New Orleans oak is a favorite place both for climbing and for meeting giraffes.

Island ghost town detailing Flagler's folly in building the Overseas Railroad.

This huge pile of volcanic boulders hides a stunning network of secret grottoes.

A tunnel of hardened lava along Maui’s famous Road to Hana.

The second largest waterfall by volume in the U.S., Willamette Falls is outdone only by Niagara in the amount of water that is pushed northward.

This Prague museum collects brutalist relics and memories from the country's former Soviet rule.

The entire length of the border is marked by a 20-foot-wide slash through the trees.

An architect's childhood fantasy treehouse made real.

Only known mainland rookery of the threatened Stellar sea lion.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

Real bones which are said to have belonged to a Polish dragon.

A 200-year-old building in the French Quarter that was to be Napoleon's home in the New World.

The world's smallest park was dedicated in 1948 as the only colony for leprechauns west of Ireland.

Dr Barnes' $25 billion private collection of art and arboretum.

The attic of a four-century-old canal house hides a clandestine church.

Home to Hollywood history and a very special salt crystal.

No one knows how this Pacific Northwest spruce tree came to have so many trunks.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

The prototype for all Nazi concentration camps.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

100-year-old shipwreck you can walk up to at low tide.

The curious underground history of keeping Paris clean.

This family mausoleum is steeped in symbolism and looks more like a fantasy location than a grave.

This massive redwood tree has a hole in the base big enough to drive through.