The Fayyum is one of the largest and most fertile of all Egyptian oases, with an overall population of about 2 million people. Unlike the Western Desert oases, which are watered by artesian wells, the Fayyum is fed by a small river, the Bahr Yusuf (Joseph's River), which connects with the Nile. The rural Fayyum measures about 65 km (40 miles) from east to west, and the lake, Birket Qarun (which classical writers called Lake Moeris), is located in the northwest. The lake was much larger and richer in wildlife in antiquity, and it was the site of some of the earliest settlements (circa 6000 BC) in Egypt.
Sights in the Fayyum include the pyramids of al-Lahun and Hawara, the Greco-Roman site of Karanis, the large singing waterwheels, and some fine agricultural countryside that includes the lake, which is pleasant to visit on a warm day. The Fayyum was especially important during two periods of Egyptian history: the Middle Kingdom, when it began to be intensively exploited for agriculture, and the Greco-Roman Period (332 BC–AD 395), when it provided most of the grain for the Roman Empire.