Sky Riders (also known as Assault on the Forbidden Fortress) is a 1976 American action film directed by Douglas Hickox and starring James Coburn, Susannah York and Robert Culp.

In Greece, the wife and children of American businessman Jonas Bracken are kidnapped by a radical group, the World Activist Revolutionary Army, who demand a ransom of $5 million for their safe return.

The kidnappers send a photograph of Ellen and the children as proof that they are still alive and, without the police knowing, McCabe uses a contact to trace their location based on a painted fresco in the background of the photo.

When Nikolidis discovers that McCabe has gone to free Bracken's family, the police decide to launch their own rescue plan and move in.

While a gun battle ensues between the kidnappers and the police at the monastery, McCabe's team and the hostages are pursued and eventually escape on their hang gliders.