These locations, according to the reports, are secret prisons used to house "ghost prisoners." Those sent to these places are held captive without being charged with any crime and are not allowed any form of legal defense.

Ghost prisoners are subject to what the CIA calls "enhanced interrogation tactics"; most others call it torture. The CIA and their operatives' methods allegedly include waterboarding, sleep deprivation, humiliation, physical beatings, electric shocks, and worse.

These secret prisons, dotted all over the world, might just be the most terrifying places on Earth.

10 Diego Garcia - Indian Ocean

Diego Garcia is an atoll in the Indian Ocean located around 1,600 kilometers (1,000 mi) south of India and 3,200 kilometers (2,000 mi) east of Tanzania. The locale is claimed by the United Kingdom as part of their British Indian Ocean Territory.

In the 1960s and 1970s, the UK deported the native people of the atoll to Mauritius and the Seychelles in order to allow the United States to construct a large naval and military base now known as Camp Thunder Cove. The installation is currently home to roughly 4,000 military personnel and independent contractors.