The museum is close to the site’s entrance. To access it from Stop 15, walk all the way back along the second processional route, returning to the Court of the Karnak Cachette at Stop 10, and continue until you meet the entrance to the Third Pylon, where you will turn left to enter the Great Hypostyle Hall. Walk along its main aisle, exit, and enter the First Court again (Stop 2). Exit the temple from the Bubastite Portal and the Open Air Museum extends right before you.