Mt Madonna County Park 7850 Pole Line Rd, Watsonville, CA 95076 $6 for parking, but free parking at Sprig Trail
If you don’t want to see too many people, Mt Madonna County Park is a great place to walk in hot weather. The area was once owned by a cattle lord named Henry Miller and there are ancient remains of his estate on the Nature Trail. The trail I took starts at the Henry Miller Site Trailhead from Lower Miller Trail -> Loop Trail and back. The Loop Trail is flat and there may be flies depending on the season.