The information here is intended to supplement the book.
This is an image of a part of Hill 10, the Battalion Headquarters of the 1st Battalion 7th Marine Regiment. Two rifle companies operated from this combat base. Patrols departed each evening to establish ambush positions hoping to intercept Viet Cong and North Vietnamese Army soldiers attempting to fire rockets into the huge Da Nang air base complex.
The tower you see in the picture has a 106mm recoilless rifle on its roof. If an enemy rocket is launched it will be seen by the 106 crew in the tower who will immediately engage the enemy rocket site. The crew scans the area with a night vision device known as a "starlight scope" for enemy movement at night. Ship binoculars are used during the day. The author spent many nights in that tower and engaged several rocket sites with the 106 while rockets were being launched.
Hill 10 was frequently attacked by rockets, mortars, and snipers. Enemy troops attempted to overrun Hill 10 but were repelled.
Hill 41 is a bit more primitive than Hill 10 where the Battalion HQ was located. During the authors time on Hill 41 it was the combat base for Delta Company, 1st Battalion, 7th Marine Regiment. The tent in the foreground was the authors home for several months. The structure with the gabled roof, behind the tent, was the chow hall. During Monsoon season Hill 41 was an island in a sea of flooded rice paddies.