A painfully obvious spy house sits right across the street from the Russian Embassy.

This titanic Catholic church in Chicago is also a refuge of the fictional cult-favorite wizard detective Harry Dresden.

These quaint cottages feature built-in signaling devices for fishermen.

A rare surviving Victorian greenhouse designed specifically to house giant water lilies.

Few of the many visitors to this resort town know of its hidden Maya ruins.

The plunge pool is a surviving relic of a rowdy royal residence.

Come for the boats, stay to explore the intriguing assortment of art.

A striking glass tribute to two sisters who suffered during Scotland's "Killing Time."

These bleak 800-year-old ruins were once the royal residence of choice for hunting in Sherwood Forest.

Used as an example in one of the first dictionary entries for "museum" in 1706.

A hidden plaque is the only reminder of the lost palace where two storied English kings were born.

Part museum, part piece of Arthurian-inspired history, this stately hall attracts King Arthur fans from miles away.

These legendary stone steps were once used to haul coffins up the rockface.

One of the few places where you can visit a cenote and Maya ruins at the same time.

A memorial to a goat culled during a foot and mouth disease outbreak guards a series of fantastical caves.

The abandoned "Ghost Mansion" was left to decay in the mountains of Northern Italy.

This tiny 19th-century tunnel was built so a man could move his cows from one field to another.

An abandoned vacation home spent a decade taking on legends. It's now taking on water.

A well-preserved Ancestral Puebloan ruin tucked beneath a desert cliff.

An underground mansion with fruit-bearing trees and grapes growing beneath the surface of central California.

The world’s highest ski resort was deserted after an 18,000-year-old glacier melted away.

One of the few surviving examples of Victorian-era public toilets now houses a small homestay.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

This historic pub has maintained much of its 1906 decor, including a small sequestered room for women, where orders were slipped through a tiny window.