Why a column on the entrance is inscribed with a verse from the Quran is one of Sicily's many mysteries.

A medieval wash house where people washed clothes in a river allegedly formed by the tears of a mourning nymph.

Down a cobblestone alleyway is a museum dedicated to Romanticism, with a secret garden.

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

An unusual ode to the late Irish playwright, complete with a squiggly bust and coffin-shaped bench.

An eccentric Victorian aristocrat's enormous collection of medieval armor and weapons from around the world.

A mysterious shape catches the eye in this 16th-century painting.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

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

Sculptor Antony Gormley used chaos theory and fractal growth to design his tallest creation.

This Underground station has been a popular filming location for decades, even before it closed.

The bridge is a secret gallery of discarded gum that has been transformed into miniature masterpieces.

Colorful murals by Jean Cocteau hide within this peaceful London sanctuary.

This coffee shop lies hidden beneath a historic church.

These mysterious Viking chess pieces spent centuries hidden on a remote Scottish island.

Murals of the wild parties once held on the frozen River Thames.

One of the few remaining examples of 19th-century London’s attempt to clean up its reputation.

This pump on the bad side of Victorian London betrayed a horrifying revelation about the water supply.

This one has sailed five times as far as Sir Francis Drake's famous ship.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

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

The rose garden in Regent's Park where Pongo and Perdita met for the first time in Disney's "101 Dalmatians."

Ship-sized kinetic sculptural fantasy.

The fierce beast perches atop a pedestal marking where the historic City of London gates once stood.