Gwen, or the Book of Sand (French: Gwen, ou le livre de sable) is a 1985 French animated science fiction film written and directed by Jean-François Laguionie, using gouache.

Gwen is a young girl adopted by a nomad tribe in a desert post-apocalyptic world.

In the desert, where only few animals, like ostriches or scorpions, can survive, a mysterious entity regularly drops gigantic replicas of everyday life objects from our world, such as bags, telephones, clocks and armchairs.

They eventually encounter other people living in an isolated city and preserving remains of the old civilisation in strange ways.

The film will be released in the United States as an Ultra HD Blu-ray by Deaf Crocodile in 2025.