Northern Ireland's Brobdingnagian stepping stones.

A hands-off space for graffiti artists to hone and display their skills.

An unusual round church in London with a Templar past.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

The atmospheric road was never meant to be so creepy.

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

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

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

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

This 17th-century street hidden beneath Edinburgh was 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.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

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

20-foot tall lamp mumbles Swedish to celebrate the holidays.

Swedish mice can dine at the Nuts of Life restaurant or take a date to the amousement park.

This antique clock once gave the most accurate time in the area.

From Coke II to Google Glass, this exhibit features some of the most spectacular commercial flops.

The marker that allows students all over the world to be late for class.

The standard measure of Lagom, a measure of what is enough.

These unique stained glass windows were designed by local children using a modern flair.

These ancient rune stones plucked from the countryside now call this university park home.

This millstone commemorates a gruesome tale that may have been the source of the city's name.

The indecision over what to place in this square was immortalized with a plaque.

A living descendant of the famous tree that helped Isaac Newton develop the theory of gravity.