This is the park that resides on the bluff overlooking Old Town. It's easy to miss the entrance, since it's a innocuous T-intersection just north of Old Town. However, if you want to learn about early San Diego, it should not be missed. This is the site of the original Spanish military camps and fort, and the remains of the fort are still visible as mounts inside the park. Years ago, archeologists dug this area up, then returned it to it's natural setting. Park below the Serra Museum and walk around the park, there are many good signs documenting what it there. Don't miss walking up the hill, there are several old monuments to military units important to San Diego, including the original Mormon Battallion that passed through San Diego in the late 19th century. Sadly, the park suffers a bit from the City's financial problems, so it's not kept up as well as it should be, but it's still one of the best hidden gems of San Diego. Rosecrans Ave., the street that you turn off from to get here, is also landmarked as California's oldest commerical street.