An indigenous culture to Central America, the Maya flourished during the lamenting Middle Ages of Europe only to mysteriously abandon their major cities prior to the 14th century A.D., leaving major architectural accomplishments lying in ruins and in the clutches of the jungles they called home. Among their other accomplishments, the ancient Mayas invented a calendar of remarkable accuracy and complexity. The Maya calendar uses three different dating systems in parallel, the Long Count, the Tzolkin (divine calendar), and the Haab (civil calendar). Of these, only the Haab has a direct relationship to the length of the year.