Richard M. Nixon Park. This tiny scrap of a park is on the intersection of Imperial Highway and Yorba Linda Boulevard, just behind a Mimi's Café. Unlike its namesake, it's quiet and unpretentious. Chino Hills State Park. There are many entrances to this large state park straddling the Orange County-San Bernardino County line, but the best is in Yorba Linda. You can't get away from the smog, but you can enter a peaceful, natural world far removed from the beige stucco that fills so much of the city and county. There are enough shady nooks and trickling streams to cool off the hottest summer day. Watch out for mountain bikers and hardcore runners. Take Fairmont Boulevard north from Yorba Linda Boulevard. Turn left on Rim Crest. Take it all the way to the end. Then start walking.