First settled by the French in 1604, French Guiana was the site of notorious penal settlements (collectively known as Devil's Island) until 1951. The European Space Agency launches its communication satellites from Kourou. It is the only portion of mainland South America still governed by an overseas nation. Low-lying coastal plains rise to hills and small mountains, and the country is made up of mostly an unsettled wilderness. It also consists of hill plateaus and the Tumuc-Humac mountains.