Project APE is a series of caches placed in 2001 in conjunction with the movie Planet of the Apes. 20th Century Fox worked in conjuction with to release caches scattered in various parts of the world in order to promote the film. They devised a sub-plot associated with the film that was unrelated to the film itself, one that was intending to reveal an "Alternative Primate Evolution" theory. A Project APE website was created in association with the cache placements. Some props from the movie were placed in the caches initially.

The series was released under a tight level of security. The original individual cachers that placed the caches did so anonymously, under the direction of officials. The caches were given Mission names, along with the number of the series (although there are two number 10's). In all, thirteen Mission caches plus a "Special Mission" cache were released. The details of the caches were released slowly, first by simply giving clues as to the state, then later the coordinates of the cache. The first finders were rewarded with a special prize.

After the film had left theatres, 20th Century Fox abandoned the caches. The Project APE website became inactive, and the few caches that had survived were later adopted by individual cachers. There are two active caches as of October 2006, found in Washington and Brazil. (The Brazilian cache was archived, but has since been re-activated.) APE caches in California, New York, and the United Kingdom were replaced by traditional caches and are no longer officially part of the series.

The surviving caches of this series continue to be popular as they has their own icon associated with the series. Although there is no longer any association with the original plotline, there are many cachers who regard these as special.

Project A.P.E. page created by Markwell, original hider of the Project APE cache in Illinois