Just 2 blocks east of Ocean Blvd in central Pacifica, this Ridge Trail gem rises from the Milagra Battery Trailhead next to a small parking area at the end of Connemara Drive. The first half-mile of trail is on an easement across conservation land set aside by the Connemara community developers. The National Park Service manages the easement and the adjacent Milagra Ridge, a Golden Gate National Recreation Area Property. Endangered Mission blue and San Bruno elfin butterfly habitat protection defined where the trail could NOT go, so the trail corridor is narrow and steep, but the Battery Trail solves that issue very well. It's an unusual trail section, on a mix of old quarry and military roads, as well as new trail that ramps up from quarry floors to steep sloping cuts, supported by hundreds of tons of imported rock. The result is a swift climb that is not too steep, but gets visitors to sweeping views quickly. In addition to hosting rare butterflies and California redleg frogs, there's historic military installations to explore, and once the trail flattens out on Milagra Ridge it is a pleasant ride or stroll across a small valley (there's hiker-only alternatives across the upper section of Milagra). From the south end of Milagra Ridge travelers can return via the same trail, or continue south a few blocks on College Drive to Skyline College, where the Sweeney Ridge Trailhead marks the entrance to another Ridge trail section linking to the San Francisco Water Department's Peninsula Watershed (that hosts 10 miles of Ridge Trail, currently accessible only via pre-arranged docent-led hikes or rides).