Like many other Pacific islands, Guam contains a number of historical features associated with World War II, especially the 1944 American liberation. The park itself consists of seven physically separated units, each providing a different insight into the Pacific War. They are located in or near the villages of Asan, Piti, and Agat, on the west side of the island facinq the Philippine Sea.

The Asan Beach Unit consists of 109 land acres and 445 water acres and is the site of the northern landing beaches. It was here that the 3rd Marine Division came ashore for the initial assault and was met by troops of the Japanese 320th Independent Infantry Battalion. War-related structures and sites, all associated with Japanese defenses, are located at Asan Point and Adelup Point.

The remains of some American military equipment lie underwater in the offshore area. Fishing, hiking, picnicking, and (for experienced persons) snorkeling and diving are permitted. Asan Point is a primary visitor area where the overall story of the Pacific War is told by means of museum exhibits. A shoreside view of the Asan landing beach and hillside battleground is located at this point. The Asan Inland Unit is directly opposite the Asan Beach Unit across Marine Drive. It was on the face of these cliffs and hillsides that the American landing forces met heavy resistance. Today, thick jungle growth or swordgrass savannah covers the area, making hiking fairly difficult. Historic sites, including a number of gun emplacements, caves, foxholes, and pillboxes, are located within this unit. There are, however, no facilities available to the public at this time. The Piti Unit is on the ridge behind the village of Piti and contains three Japanese coastal defense guns in good condition.

The Mt. Tenjo/Mt. Chachao Unit is on a ridge line between Mt. Tenjo and Mt. Chachao. This unit provides a scenic overview of the surrounding area, including Apra Harbor and Orote Point . The few historic remains here include foxholes and a World War I American gun emplacement. Hiking is permitted along the unimproved trail. The Agat Unit is the site of the southern landing beach. It was here that the First Provisional Marine Brigade and the 305th Regimental Combat Team of the 77th Army Division came ashore. They were met by the Japanese 1st Battalion, 38th Infantry. Apaca Point, Gaan Point, Bangi Point, and Bangi Island contain historic sites and structures, including caves, bunkers, latrine foundations, and more than 10 pillboxes, some in excellent condition. The beach and offshore area here are relatively unspoiled and provide a good impression of how they looked in 1944: Several pieces of American military equipment still lie underwater near the edge of the reef. Picnic areas are at Rizal Point and Apaca Point. Fishing, hiking, picnicking, and (for experienced persons) snorkeling and diving are also permitted.

The Mount Alifan Unit is behind the village of Agat. The slopes of these hills saw heavy fighting between the Marines and the defending Japanese forces. Today the area is covered with historic sites and debris. Access to the area is fairly difficult, allowing only limited hiking. The Fonte Plateau Unit, site of a former Japanese naval communications center, is currently undeveloped. Park headquarters and the T. Steil Newman Visitor Center were located in the Asan Beach Unit in the village of Asan before being wiped out by Super-typhoon Pongsonga in December of 2002. It is a testament to the power of this storm that Park Headquarters and the Visitor Center are still closed. Plans are advancing for a new museum and visitor center.

(Above units link to the National Park Service, War in the Pacific site.)