Pinus torreyana, the rarest native pine tree in the United States, enjoys a 1,700-acre sanctuary at the northern edge of La Jolla. About 6,000 of these unusual trees, some as tall as 60 feet, grow on the cliffs here. The park is one of only two places in the world (the other is Santa Rosa Island, off Santa Barbara) where the Torrey pine grows naturally. The reserve has several hiking trails leading to the cliffs, 300 feet above the ocean; trail maps are available at the park station. Wildflowers grow profusely in spring, and the ocean panoramas are always spectacular. When in this upper part of the park, respect the restrictions. Not permitted: picnicking, smoking, leaving the trails, dogs, alcohol, or collecting plant specimens.
You can unwrap your sandwiches, however, at Torrey Pines State Beach, just below the reserve. When the tide is out, it's possible to walk south all the way past the lifeguard towers to Black's Beach over rocky promontories carved by the waves (avoid the bluffs, however; they're unstable). Los Peñasquitos Lagoon at the north end of the reserve is one of the many natural estuaries that flow inland between Del Mar and Oceanside. It's a good place to watch shorebirds. Volunteers lead guided nature walks at 10 and 2 on most weekends.