The U.S. attacked the island of Peleliu in 1944, in the belief that it had to do so to get at the Philippines. What was expected to be a three-day affair stretched into 73 days, in scorching heat of over 110 degrees Fahrenheit. Seventy-five years later, remains of this battle with Japan's formidable forces are still everywhere on the ground.
For a no-holds-barred account of Peleliu and Okinawa, read E.B. Sledge's book With the Old Breed. Sledge was a private straight out of boot camp, depolyed into the 1st Marines.