Encompassing 575 square kilometres of jungle and thousands of ruins, The Tikal National Park protects an ancient Mayan citadel in northern Guatemala which most likely dates back to the 1st century A.D. The ruins were officially discovered in 1848 and were declared a UNESCO World Heritage Site in 1979. The iconic Temple of the Grand Jaguar which contains the tomb of one of Tikal's greatest rulers, Ah Cacau (Lord Chocolate), and the Temple of the Masks tower over the plaza in the centre of the ancient city which contains around 3,000 ruins spread over an area of about 16 square kilometres. Tikal is also part of the one-million-hectare Maya Biosphere Reserve created in 1990 to protect the dense forests of the Peten Department of Guatemala which started to disappear at an alarming rate due to population pressures, illegal logging, and damaging agricultural practices.