The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

Scattered throughout London are ancient remnants of the city's former bounding wall.

A Roman spa buried deep beneath the City of London.

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 Harry Potter films.

The site of London's first coffee house has been serving refreshments of one kind or another for 360 years.

The last four extravagant street signs of London's historic banking street.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

The beautiful baroque library of the Hapsburg empire.

Baroque celebration of the end of the Great Plague of Vienna.

The solemn exterior conceals an opulent interior of this 17th century church.

An exquisite Baroque church in Vienna's old town.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

This Ukraine alleyway has become its own little island of forgotten things.

Ukraine's oldest operating pharmacy now offers guests a fascinating walk through apothecary history.

This street has over a half-dozen names, all at once.

This beautiful natural train tunnel is said to grant the wishes of visiting lovebirds.

The last planned Soviet city was built for the former residents of Pripyat after the Chernobyl disaster.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

This derelict superstructure was a very important warning system for the Soviet military.

The spectacular Roshen Fountain show lights up the night sky all summer long, until it "hibernates" under the ice waiting for spring to come.

Dine amidst exotic plants at this former royal greenhouse.