Let’s learn about some of the most interesting abandoned settlements, from ancient ruins to modern ghost towns.

Angamuco, Mexico

The city of Angamuco in North America, built around AD 900, is thought to have had 100,000 citizens and included pyramids, road systems, vegetable gardens and ball courts. It was a major center for the Purepecha, competitors to the Aztec peoples. Both of their cultures were destroyed in the 16th century when Europeans introduced bad diseases there.

Termessos, Turkey

Alexander the Great once compared this great city — located 1,000 meters up a mountain — to an eagle's nest. And despite surrounding it in 333 BC,the failed to take it. The most famous site of this city was a Roman-style theater. The city was abandoned around 200 AD because of a big earthquake.

Gedi, Kenya

Lying on the Indian Ocean coast, among thick forests, this settlement is thought to have been founded around the 13th century. Gedi had running water and flushing toilets. Scientists have also found vases from the Ming Dynasty and Venetian glass on the site. Its abandonment several centuries later still remains a secret.

Mohenjo-daro, Pakistan

Founded around 2500 BC, this Indus Valley city had a street system and a complex drainage (排水) system. The city developed successfully, with up to 40,000 settlers living off the floodplain which was rich in good soil,and traded with Mesopotamia. However, the cause of its decline from 1900 BC still puzzles scientists today.

Priyat, Ukraine

After reactor No.4 at Chernobyl exploded in April 1986, giving off deadly radiations (放射物) into the atmosphere, several nearby settlements were moved elsewhere. Among them was Priyat, once a city built to house nuclear (核能) workers, Three decades later, this place had been repopulated by deer, wolves and other animals. You can now tour the town and get a radiation screening when you leave.

Devon Gallagher, a college graduate from Philadelphia, wants the world to know exactly here she's been during her worldwide vacation in a special way.

The traveler, who was born with a bone disease, had her right leg amputated (截肢) at the age of four. Although the amputation caused setbacks for Gallagher early on, she now sees it as nothing short of inspiration for living her best life.

To spread that message, Gallagher has taken to social media, where she shares photos of her travels across the globe, but instead of simply using a geo-tag, she writes her location across her artificial leg before taking a picture.

Now she has been taking pictures across the Continent, which show her cycling over the canal in Amsterdam, relaxing on a wall overlooking the city of Barcelona, posing with a waffle in Brussels, taking in the spectacular Parthenon temple in Athens and enjoying a river cruise in Budapest, all with the well-known locations written on her artificial leg.

“I get a new leg every two years and I can choose the design on it. One day I had a sudden thought to get a chalk-board, "Gallagher said. "My mum and grand-mother weren’t too keen on the idea, but my friends thought it was great and told me to go for it, so I did.”

Gallagher said people often stare when she’s writing on her leg, but once she shares the photos she receives only positive feedback."My leg hasn’t stopped me from doing anything I've wanted to do, " she said. "I don’t know if it's my determination to prove to myself that I can do it, but regardless, I've been able to keep up with my peers and lead a pretty great life.”

Gallagher shows us that you should never let anything stand in the way of your dreams. And if life gives you an artificial leg, make art.