A unique seaside cave where Aleister Crowley faked his own death.

The last bastion of Roman presence north of the Alps looms over a German town.

The birthplace of Karl Marx is now a museum dedicated to the communist revolutionary's life and work.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

The remains of the great moral philosopher reside in a university in London.

A community of artists and entrepreneurs seeks a simpler life on London's waterways.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Go inside to really appreciate this 500-year-old technological masterpiece.

A mysterious plaque to the even more mysterious "Fr. Pat Noise," killed in "suspicious circumstances."

The somber sculptures commemorating Irish Famine on the river Liffey in Dublin.

A devastating booze inferno poured through the streets, claiming several victims who drank it.

A sacred well steeped in Pagan roots on the West Coast of Ireland.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

This 14th century tower house was once the home of Irish poet W.B. Yeats.

The largest oak in England is said to have been the hideout of Robin Hood and his Merry Men.

His body was found mysteriously preserved in a Swedish mine over 40 years after his initial disappearance.

Anatomical cabinet holds unexpected treasures.

The first botanical garden, a feather in the cap of the Grand Duke of Tuscany.

It houses the remains of a 17th-century version of the Titanic.

The oldest operating pharmacy in the world features 800-year-old recipes.

This strange bovine gargoyle is said to have been put in as a passive aggressive form of revenge.

The famous sculptor left his mark on this Italian wall in an internationally protected example of street art.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.