Lake Qarun

A large salt lake filling the lowest part of the Fayoum depression, some 43 metres below sea level. The northern shore is empty desert cliff; the southern shore has the villages, the fish restaurants and the road. Sunset over the water, with the escarpment behind, is the reason most people come.

What to do

• Eat fish — the lakeside restaurants serve the day's catch, usually tilapia, simply grilled
• Birdwatch — the lake is a significant wintering ground; flamingos, herons, spoonbills, waders and large numbers of ducks between October and March
• Qasr Qarun, at the western end — a well-preserved Ptolemaic temple of Sobek in the ruins of ancient Dionysias
• Take a boat out, or simply walk the shoreline in the late afternoon

The lake is what remains of Lake Moeris, which in antiquity was vastly larger and, crucially, fresh. The Fayoum is fed by the Bahr Yussef, a natural channel branching from the Nile, and Middle Kingdom engineers widened and regulated it to control how much floodwater entered the basin.

The effect was a reservoir: excess flood was stored in the depression and released back towards the valley when the river was low. It was one of the earliest large-scale water-management schemes anywhere, and it turned the Fayoum into an unusually productive region — which is why Amenemhat III built his pyramid and his Labyrinth here rather than near Memphis.

Shrinking and salting

Since the ancient regulation ended, the lake has had no outflow. Water leaves only by evaporation, while agricultural drainage keeps feeding salts in, so it has been getting smaller and steadily saltier for centuries — it is now saltier than the sea in places, and the fishery has shifted to species that tolerate it.

The trend is a live environmental problem for the Fayoum rather than a historical curiosity, and it is visible on the shore: old buildings and jetties now stand well back from the water.

Older than any of it

The cliffs on the northern shore hold fossil beds from the Eocene, the same sequence that surfaces at Wadi Al-Hitan. Early primates were found here — species that sit near the base of the family tree that leads to monkeys, apes and us.