MacArthur and his men held out for almost 4 months in this tunnel. The enemy had plan to take the island in less than a week. Designed by MacArthur, they had no idea it would serve them well in WWII. Later in the war MacArthur and his men would have to re-take the island and this tunnel. It took 2700 troops with an impossible jump onto the island to surprise the 6000 Japanese marines that were in over 400 tunnels, all over the island. Fortunately for the Americans, all the tunnels and their guns were pointed to the sea! Nobody thought that Topside and Middleside would be the invasion location.