Widely considered to be the cradle of civilization, Mesopotamia brought significant cultural developments. The art of Mesopotamia rivalled that of Ancient Egypt as the most grand, sophisticated and elaborate in western Eurasia from the 4th millennium BC until the Persian Achaemenid Empire conquered the region in the 6th century BC. The main emphasis was on various, very durable, forms of sculpture in stone and clay; little painting has survived, but what has suggests that, with some exceptions, painting was mainly used for geometrical and plant-based decorative schemes, though most sculptures were also painted. Cylinder seals have survived in large numbers, many including complex and detailed scenes despite their small size.