The Valley of Gwangi is a 1969 American western-fantasy film directed by Jim O’Connolly and written by William Bast. The film is also known as Gwangi, The Lost Valley, The Valley Time Forgot, and The Valley Where Time Stood Still. It was filmed in Technicolor and is known for its creature effects provided by Ray Harryhausen, being the last prehistoric-themed film animated by him.