War in the Pacific Memorial Park Overlook - Nimitz Hill, Guam: This site has historic reference. This virtual tour shows the valley where US Marine Forces climbed up the hills after storming Asan Beach below. The main attraction at this memorial park is a large wall listing the names of men, women and children who were killed during World War II. Japanese Imperial Forces occupied Guam from 1941-1944; US Military Forces recaptured Guam on July 21,1944. A grateful people have since celebrated that day as Liberation Day.