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

Paleoamericans built these ancient walls high in the Colorado Rockies as part of an extensive hunting system.

This pond is so stunning it looks like you've stepped into one of Monet's masterpieces.

The centuries-old obelisk may have inspired J. R. R. Tolkien.

The ruins of an abandoned medieval city where the last Byzantine emperor was crowned.

A long-overdue monument to the forgotten British men drafted into the coal mines during World War II.

The giant statue and its model solar system honor the native Pole who declared that the Earth revolves around the Sun.

There's a crumbling old mansion inside the Smithsonian National Zoo.

A medieval house adorned with enigmatic carvings, including one of a man displaying his masculine attributes.

The mile-long pier stretches from a ruined fortress out into the Baltic.

This staircase in a lush tropical grotto was built by enslaved laborers and renamed to honor Queen Victoria's role in ending slavery in the British Empire.

The 16th-century church was kept in its ruined state as a reminder of the casualties of World War I.

A network of concealed passageways lies within a busy London Underground station.

This beautifully verdant lagoon is tucked below a massive volcano in a crater atop a black pebble beach.

This lonely tomb is all that remains of a once-bustling ancient trade hub visited by Marco Polo.

This historic funicular system combines the old with the new while offering delightful views over the surrounding valley.

The legendary bathing site of a Moorish queen is actually part of a Roman fish farm.

This museum inside a museum tells the story of London's timepieces.

The collapse of the brand-new dam caused one of the worst floods in British history.

This remarkably intact, 260-year-old cargo ship is only visible at the lowest of spring tides.

A small Byzantine church lost in the middle of the mountains of southern Italy.

Modern megaliths form this work of cosmic, Celtic landscape art.

The now-overgrown beach resort was once frequented by Yugoslav military elite.

A striking 500-year-old mansion provides an unexpectedly sublime home for live deer and a menagerie of exotic stuffed animals.