This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

An impressive armored bronze effigy marks the tomb of one of the medieval era's greatest warriors.

A wonderfully eccentric Victorian-era museum and library.

One of the few standing Roman lighthouses and a labyrinth of tunnels are a couple of the secrets at this historic castle.

A vintage penny arcade hidden in the back of a fun fair-themed bar.

The rotting skeleton of a shoreside fun fair that was destroyed by fire and storms still haunts the Brighton ocean view.

A grand Wetherspoon pub set in a former opera house dating back to 1902.

This centuries-old hotel hides a network of secret cellars and passages once used by smugglers.

In the middle of an extremely unforgiving and desolate high desert is the most secret military facility in the world.

A Norwegian-born sculptor created these soaring guardian angels at the entrance to Hoover Dam.

This Las Vegas casino boasts one of only three spiral escalators in the United States—an engineering wonder.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Paris' fabled purveyor of exotic taxidermy and natural history curios.

The video game-themed street art first popped up in the French city.

A fire once nearly devoured this gorgeous 14th-century Gothic cathedral.

This snug medieval lane is one of the narrowest streets in the world.

The European towns of Brașov and Râșnov each have proud signs reminiscent of the Hollywood sign.

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

This elaborately decorated, fairytale-like Romanian royal palace is one of the most striking castles in Europe.

Romania's triumphal arch looks out over Bucharest.

A plaque marks the spot where the saint was shoved off the Charles Bridge and into the river.

What looks like a suicide in progress is actually a statue of Sigmund Freud.

The first museum in the world devoted to sexual gadgetry.

Macabre astrological automaton clock dating to the late 1400s.