Graffiti from the 16th and 17th centuries cover the walls of this part of the Tower of London.

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

Giant, friendly pelicans in Central London, the most unlikely of places.

This stunning iron gate designed by Modernist architect Antoni Gaudí is filled with mythic symbolism.

A once-secret library of Freemason history in Catalonia.

A beautiful but toxic fountain of mercury.

Holy Grotto of Montserrat Monastery holds one of Europe's mysterious black Madonnas.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

The final resting place of a poisoned lover whose death was at the center of one of Glasgow's most sensational murder trials.

Climb this overlooked gem's spiral staircase and you'll be rewarded with spectacular views of Glasgow.

Glasgow's memorial to the International Brigade volunteers from Great Britain who fought and died in the Spanish Civil War.

A serene public space nestled within the remains of Glasgow’s Victorian maternity hospital

An icon of the Battle of Britain is frozen in flight in a grand Victorian museum.

The old tradition of drying laundry on poles in the public green is still guaranteed by Glasgow city law.

A scattered trail of street art adds a pop of color to the city's stark structures.

The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

The only monument to name all of the passengers and crew who died on the RMS Titanic.

A giant sculpture of the legendary "Salmon of Knowledge" celebrates the return of fish to Belfast's River Lagan.

A palatial former bank building now houses what may be the poshest art venue (and former Tesco) in Belfast.

The ship built to ferry passengers and goods to the doomed Titanic is now the last remaining White Star Line vessel.

A museum marks and documents the site of the Titanic's launch.

This Victorian-era public house has set the standard for pub-style elegance for over a hundred years.

For part of the year, this innovative greenhouse is painted white to keep the plants from getting scorched.