Garden of Bones (Qarth)

"[...] the desert around their walls is called the Garden of Bones. Every time that Qartheen shut their gates on a traveler, the garden grows."

- Ser Jorah Mormont

The Garden of Bones is the desert surrounding the city of Qarth, lying between the port city and the Red Waste. It is called so because it is filled with the bones of travelers who have been denied entry to Qarth and have perished to thirst and exposure.

Season 2
Daenerys Targaryen and her khalasar cross the Garden of Bones after being invited to meet the Thirteen, the Qartheen ruling council, through her bloodrider Kovarro. After meeting with the Mother of Dragons before the walls of Qarth, the Thirteen turn her away, unconcerned with the fate of the last Targaryen and her people. Faced with the prospect of having led her people to their deaths, Daenerys threatens the Thirteen to destroy Qarth but they remain unfazed, as her dragons are not yet grown. One of the Thirteen, Xaro Xhoan Daxos, defies his fellow dignitaries and invokes Sumai, a blood oath by which a Qarteen citizen may vouch for an outsider, and gets the doors of the city to be opened for Dany and her followers.

In the books
In the A Song of Ice and Fire novels there's no mention of the desert around Qarth or if the Qartheen refuse entrance to travelers, leaving them to die. The name of the Garden of Bones may be a reference to a ruined and abandoned city in the Red Waste in which Daenerys and her khalasar take refuge and which her Dothraki name "Vaes Tolorro", City of Bones, for the blank and chalky façades of its buildings.