This unreal Portuguese palace looks as though it's made from a pile of different castles.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

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

Northern Ireland's Brobdingnagian stepping stones.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

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

A little slice of Japan and its aesthetics in London's Holland Park.

This macabre painting of a Shakespearean scene looks like something out of a nightmare.

The next-door homes of two very different musicians, George Frideric Handel and Jimi Hendrix.

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

Its collection includes a broad array of social, geographic, graphic design, and political history.

A quartet of tiled art pieces adorn the floors of this prestigious art museum.

Originally meant to hold a statue of King William IV, this support sat empty for years. Today, it hosts a rotating cast of public artwork.

London’s first road overpass is so old that it was originally built for horse-drawn carriages.

Hear the quietest sound from across the dome.

This sprawling, Brutalist estate feels like a city within a city.

A 2000-year-old Roman amphitheater lies just below Guildhall Yard.

The library houses an incredible collection of some of the world's most impressive books and manuscripts.

Grotto replete with mystical designs laid out in glued shell mosaics.

The unlikely myth that this bridge was designed by Sir Isaac Newton is quite a tribute to its clever design.

Students can borrow artwork from this gallery to display in their own residences.

This hill is all that remains of Cambridge’s former castle.

The stoic structure boasts a whimsical set of stained glass art commemorating Lewis Carroll.