The Allied Gardens/Benjamin branch library opened in 1965. The branch is among the smaller ones in the system at around 4,000 square feet, but has a really large collection of books for its size as well as a community meeting room, outdoor patio, and a separate reading room for periodicals. Like many other of the smaller branches, its high ceilings, natural light, and open layout make the library feel bigger than it actually is.

Geographically, the Allied Gardens neighborhood kind of of expands concentrically around the area in which the library is located, which also includes a large public park, swimming pool, recreation center, and middle school. Allied Gardens is primarily residential and composes the northwestern component of the Navajo region of San Diego, which also includes Grantville, San Carlos, and Del Cerro. To the north, the neighborhood is bounded by the San Diego river, Mission Gorge, and Mission Trails Regional Park.