Ed Levin County Park in Milpitas is a popular park with a lake, dog park, and hills. The most popular trail in this park is the Agua Caliente Trail -> Calera Creek Trail loop which is a 3.7 mile hike that starts at the Tularcitos trailhead near the dog park. You get views of Sandy Wool Lake, Minnis Ranch, and the cities nearby. For a more difficult hike to tackle, you can take on the Monument Peak Trail.