The Presidio San Agustín del Tucsón is a partial reconstruction of the Spanish military fort that gave Tucson its name, at the heart of downtown. The original adobe walls were torn down and built over in the late nineteenth century; what stands today is a faithful rebuild on the original footprint, completed in 2007.
Inside the walls there are costumed interpreters, a Spanish-era kitchen, a torreón (defensive tower) you can climb, and a small museum on the four cultures — Tohono O'odham, Spanish, Mexican, American — that have lived here. Small entry fee. Best combined with a wander through the surrounding historic block.