One of the oldest scientific gardens in Britain, containing more than 13,302 plant species in its core collection.

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

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

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

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

A museum that cashes in on its infamous little people while teaching you a thing or two about the Irish fey.

One of Ireland's most infamous prisons for rebels including men, women and children.

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

The comedy and tragedy of Oscar Wilde is preserved in a Dublin park, captured in a sculpture of colorful stone.

A pair of mutilated bronze octopuses slump at the base of the monument honoring California's admission to the U.S.

A playing field for a popular French past time can be found tucked away in a quiet corner of Golden Gate Park.

San Franciscans leave gifts and messages for the magical beings that live behind the tiny, mysterious door installed on a tree in Golden Gate Park.

The legendary statue-hating superintendent of Golden Gate Park is honored with... a statue.

The grand, column-fronted, sculpture-adorned home of the ambitious digital library.

The best place in the park to test out your throwing arm.

Art in the form of a winding, man made crack in stone.

A masterpiece in Golden Gate Park by virtue of the artist’s debt.

A free, public museum dedicated to the fascinating science of sight.

A pair of slides and a tree-lined stair corridor have been an urban oasis for nearly 40 years.

San Francisco's oldest operating hotel, with a Victorian atmosphere and a "haunted" fourth floor.

A promotional sun clock on the site of San Francisco's great raceway.

San Francisco's most expensive hotel suite includes a secret passageway rumored to have been used by JFK.

Amazing meticulous gardens of personal wood carvings, Hydrangea, Canna, and many other flowers.

Nuclear waste dump site now an environmental sanctuary.