The perfectly preserved underground rooms where Churchill plotted the war against Germany.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Every equinox this Maya pyramid puts on a spooky ancient light show.

An Aztec temple, the largest man-made pyramid in the world, sits buried in earth with a Spanish church set on top.

The world's largest military aircraft cemetery.

The Decoy Capital of the World.

This medieval Estonian tower provides access to a series of tunnels that have been home to soldiers, punks, and fine art.

The world's tallest statue of an American hero.

One of the first big sculptures anywhere in Australia.

The 340-year-old house that inspired the classic Nathaniel Hawthorne novel.

Famously misunderstood wonder of the ancient world

A local farm's collection of unusual structures from a now defunct storybook amusement park.

Remnants of a storybook amusement park hidden behind a strip mall.

This bridge is the first to be made entirely from iron, but designed like it was still made of wood.

The house that Frank Lloyd Wright "(shook) out of his sleeve at will" at the age of 86.

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

The oldest museum in Borneo is a cornucopia of rare taxidermy and human skulls.

A marvel of Byzantine engineering under the streets of Istanbul.

Taxidermy of the racing horse with a huge heart, who inspired hope in the Depression.

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

Home of the International Space Hall of Fame.

A massive Montreal stadium that has seen nothing but trouble since its inception.

Hear the quietest sound from across the dome.

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