Don't stop driving until you find this hidden stone yard in Oak Cliff, snuggled against the Trinity River levee. Drive in and weigh your vehicle. Then wander the rows of stone to your heart's content, admiring rocks hauled from all over the United States. Even though it's near downtown, this is a lost bucolic corner of the city: You'll scare up some cottontails as you search. Load up what you want, weigh out, and pay up. They also deliver.