A 1,215-foot tunnel transports pedestrians beneath the River Thames.

Eighty million natural history specimens call this gargantuan museum home.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.

This memorial to the victims of the Romanian Revolution of 1989 is often compared to a potato on a skewer.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

This once-derelict building is now one of the most beautiful bookstores in the world.

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

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

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

Visit an imposing 13th-century Transylvanian citadel lurking not far from the region's more heavily touristed attractions.

The ancient Greek Titan guards this massive dam holding a lightning bolt to symbolize electricity.

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

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

Romania's "Red Ravine" is a little-known natural wonder that bears a resemblance to the Grand Canyon.

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

Climbing to the top of the cathedral's bell tower offers sweeping views of these medieval ruins.

This hauntingly beautiful cemetery outside a medieval citadel is full of winding paths and ivy-covered graves.

A medieval church built up to defend its village.

Something's watching you.

Nine centuries-old fortresses guard the walls of this medieval Romanian city.

This massive underground salt mine now holds a sci-fi theme park in its depths.