Wadi Al-Hitan, Natural monument in Faiyum Governorate, Egypt

Wadi Al-Hitan is a paleontological site in Egypt's Faiyum Governorate where fossil whale skeletons lie exposed on pale sand within a roped boundary. The bones, pale tan to light brown, include a blocky skull, a chain of vertebrae and long splayed ribs. Above them rises a mound of tan sand and gravel capped by a band of yellow-ochre, gray and brown stratified rock.

The area lay beneath the Tethys Sea during the Eocene period about 40 million years ago, a shallow ocean where these whales lived. After death, the animals were buried by sediments and their bones remained intact over millions of years until they were later exposed.

The Arabic name Wadi al-Hitan means "Valley of the Whales", from wadi (valley) and hitan (whales). The site lies within the Wadi al-Rayan protected area, and its open-air museum displays whale skeletons in the positions where they were found, with low rope barriers around some specimens. Local craftsmen used clay, pottery and palm-fibre rope for the trail signs and markers inside the valley.

The site lies in the Wadi al-Rayan protected area, about 150 km southwest of Cairo; a 38 km dirt track and marked trails lead to the fossil areas. Signage, toilets and a cafeteria are provided, and the open-air museum keeps skeletons roped off so visitors view them without touching. Only around 1,000 people reach the valley each year, so guided tours or camel treks are the usual way in.

At some locations, visitors can see remains of hind limbs that show these marine animals descended from land-dwelling ancestors. Such anatomical transition features make the area especially valuable for studying evolution.