A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

The underground sanctuary of a mysterious ancient cult.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

One of the most controversial statues in Romania is an emperor with no clothes.

Romania's triumphal arch looks out over Bucharest.

A medieval church built up to defend its village.

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

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 bust of Romania’s most notorious ruler, Vlad Dracula aka "Vlad the Impaler," keeps watch over the ruins of his medieval court.

This solitary monastery may hold the remains of Vlad the Impaler (but probably not).

This fairy-tale castle would make Dracula (who is said to have been imprisoned there) jealous.

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

The legendary cliffside castle of three-time Voivode of Wallachia, Vlad the Impaler.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

An overlooked memorial honoring the local Washington residents who died in World War I.

A fitting attraction for the corn capital of the world.

In which a local geological marvel becomes a quaint roadside attraction.

The world’s first penitentiary, meant to be humane, drove men insane.

An annual extravaganza of Broadway theater memorabilia.

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

The only structure left with direct ties to the Salem witchcraft trials of 1692.