Why is Gitmo still open?

Just a reminder that people have been held without charges for years by the US military. Obama said he'd close the prison in Gitmo back in 2007. He's had a couple terms, Trump has been in three years, and here we are over a decade later.
What makes Guantanamo different?


I hate to link to the New York Times, but a prisoner's drawings of American torture techniques are horrifying:
Published for the first time, sketches drawn by Abu Zubaydah — the first prisoner known to undergo “enhanced interrogation” — show the torture he was subjected to during the 4 years he was held in secret prisons by the CIA