Stonewall rock has consistently the best rock in the Woodcrest section of the Vacaville Boulders. Basalt all the same, the rock is less vertical than most of the other climbing in the area, and is a little more weathers, making the holds more slopey in contrast with the typical jagged jug of the rest of Vacaville.
Named because of the 12" stone wall that surrounds most of the climbing on the rock, the area inside the stone wall (except for broken glass) is a nice flat place to land. While the stone wall certainly gives a nice place to rest, it is a little too close to the rock sometimes, so having a spotter around is a good idea.
There are also several harder routes in the slot behind the main part of Stonewall Rock, though the slot is narrow enough to break your tailbone if you fall. Stonewall Faces Northeast, leaving at least some of the rock in the shade most of the time.
All routes top out into the loose rock above and walk off to the left edge of the stone wall. If you got pads below, jumping off past the final move of the route will save you the rather lengthy and somewhat precarious downclimb.
The Stonewall Traverse (V1) heads across the face right to left is an awesome 20' route of sustained V1 traverse moves.
Approach time: 6 minutes.
From the gate heading into the open space, head left and then uphill on the dirt road about 150 yard until you come to another gate which heads into the open space on the right side of the road, and may or may not be locked. Worm your way into the open space, and continue up the path which heads uphill and is directly in front of you.
Follow this path uphill about 200 yards past several of the other rocks which hold problems, until a short (12") stone wall surrounds a large rock just to the left of the path. If you're not sure, a 5' boulder hides a slotted cave with some SKETCHY climbs up an overhung face on the backside of the rock.
This is Stonewall Rock.
Mountain Project's determination of some of the classic, most popular, highest rated routes for Stonewall Rock: