Made of giant chains and hung with shackles, this iron cross honors those unknowns who perished under American slavery.

A theme park that suffered massive flooding during Katrina was abandoned, and now proves irresistible to trespassing explorers.

A memorial for a young woman and her ghost, which are claimed to have caused countless deathly shipwrecks.

This medieval castle overlooking the Elzbach river looks just like it did hundreds of years ago.

The National Railway Museum in York is the largest railway museum in the world, attracting almost 1 million visitors per year.

The world's oldest known salt mine.

Baroque celebration of the end of the Great Plague of Vienna.

The Slovenian architect designed many landmarks in the capital city, including his own dream house.

The "dragon babies" of southeastern Europe.

A miniature train-ride through Slovenia's largest cave system.

A whimsical bridge adorned with decorative dragons.

This one-time health resort was used by aristocrats around the world.

Where Venice's gondolas go for a tune-up.

The only museum with its curator—and her pets—buried inside.

One of Catholicism's four major basilicas has a series of papal portraits that are said to predict the end of the world.

An extensive collection of reliquaries containing the bones of saints housed in the largest Catholic church in Venice.

Da Vinci's equestrian statue, 500 years in the making.

The "Greatest Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

Stone memorial that's said to predict the death of the pope and the site of the Cadaver Synod.

This strange bovine gargoyle is said to have been put in as a passive aggressive form of revenge.

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

Built to repay the sins of the father, this church is home to one of the most valuable works of Western art.

Water and windows define this defensive Italian well.

A lover's walk between hilltop towns, decorated with graffiti love notes.