ALG-375, Porthole Arch, North Idou Maze Area. 1.5 meter height (measured). From the secret chamber, cross under ALG-374 (Exit Arch) and proceed out into a large chamber. Porthole Arch is located on the left. The upper part of ALG-377 (Triple Arch) is visible through the arch in the photo. This terrific shot can be taken only around 10 am.