Remnants of cells from the most notorious London prison may lie in the basement of a rare Victorian Gin Palace.

A mysterious carving from 17th-century London seemingly depicts a young boy sitting on a bread basket.

London's amazing modernist public square that never was.

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

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

A mysterious pair of mice eating a piece of cheese is London's smallest public sculpture.

The Great Fire of London and the regulation of one-way streets both started in this alley.

The commemorative stone column conceals a secret laboratory.

Though they've since been renamed, these two streets hint at Dublin's darker days.

A particularly disconcerting tribute to Irish martyrs.

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

This massive monument has been telling the time for 150 years—at a slight angle.

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

The statue honors a beloved bird that once roamed St. George's Market.

The last Victorian market in Belfast.

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

Northern Ireland's Brobdingnagian stepping stones.

These murals stand as reminders to the troubled history of this Northern Ireland city.

After a traumatic encounter with a six-foot eel, one Galway baker started making a daily loaf of sourdough in its shape.

The oldest inn in Kilkenny was established by the first convicted witch in Ireland.

This neon landmark has been posing this deadpan question to follicly-challenged Dubliners for over 50 years.

An 80-year-old plane tree is devouring an iron bench at Ireland's oldest law school.

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

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