A former Latvian headquarters of the brutal KGB secret police is now open as a grim reminder of their atrocities.

Romania's triumphal arch looks out over Bucharest.

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 doorless 20th-century elevator doesn't stop or slow down.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

Macabre astrological automaton clock dating to the late 1400s.

This alley off Edinburgh's Royal Mile contains remnants of the city's seedier history.

This obscure walkway links Edinburgh’s Old Town with one of the city's prime vantage points.

A labyrinthine network of chambers with a storied past hides below Edinburgh's South Bridge.

Remnants of the 16th-century defensive wall still stand unassumingly within Edinburgh.

This otherwise ordinary close on the Royal Mile constituted the end of the world for Edinburgh’s poorest residents.

The most loyal of little dogs, or a Victorian era publicity stunt?

The final resting place of soldiers' loyal canine companions.

A sweet symbol marks the place where torturous executions were once carried out.

360° views of the city plus five floors of optical illusions and hands-on science.

Famously misunderstood wonder of the ancient world

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

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

Banksy gives themself artistic license with this piece of London street art.

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.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.