The long history of Greece is extremely complex and includes the overlay of influences of the Hittites and Persians whose empires reached parts of Greece. In 1829, Greece became independent from the Ottoman Empire, however, the imprint of the Byzantines and Ottomans are difficult to separate from the architecture that is identified as vernacular. The Aegean, Ionian, and Mediterranean Seas, and the Pindus Alps and Rhodope mountain ranges occupy the major part of the Greek landscape and established the various climates found. These factors, along with the various cultural influences and the presence of earthquake activity have contributed to the different types of vernacular architecture that are still found.