What's the must-see thing in San Diego?

Balboa Park, not the beaches. San Diego's coastline is worth a day, but you can see a Pacific beach in a dozen California cities. Balboa Park is the thing you can only do here. The park north of downtown holds the San Diego Zoo (founded 1916), the Old Globe Theatre, and the cream-and-terracotta exposition pavilions that line El Prado, the park's central pedestrian corridor. Most first-timers treat the Zoo as a separate trip. It isn't. The Zoo sits in the park's northwest corner, and a morning there flows into an afternoon walking east along the promenade past museums and free botanical gardens. You'll smell eucalyptus along the Sixth Avenue entrance before you see the first pavilion. The bark peels in long strips that crunch underfoot, and the tree canopy holds the morning air 3-4°F cooler than Mission Beach on a typical August day.

Buy San Diego Zoo tickets online the night before. General admission currently runs about $67 for adults, $57 for children 3-11. Get there when the gates open. The first 90 minutes are the best. The animals move in the cool morning air, the big cats pace instead of sleeping, and the aviaries are loud with feeding calls. By 11am the tour buses arrive and the popular viewing areas back up 15-20 minutes deep. After the Zoo, walk south on the promenade. The San Diego Museum of Art (founded 1926) charges $20 general admission. The Timken Museum of Art (founded 1965) is free, and it holds a Rembrandt and a handful of old masters in five small rooms. You might spend 40 minutes there. The Spanish Village Art Center, a cluster of 37 studios built for the 1935 California Pacific International Exposition, is also free. Artists work in open doorways, and the smell of oil paint and turpentine drifts into the jasmine-heavy courtyard air.

Cabrillo National Monument, on the tip of Point Loma, is the second thing worth your time. The monument (established 1913) marks the spot where Juan Rodríguez Cabrillo's expedition landed in 1542, and the view from the 1855 Old Point Loma Lighthouse covers the harbor, downtown, Coronado, and on clear mornings the Coronado Islands 18 miles south in Mexican waters. Entry is $20 per vehicle, free with an America the Beautiful pass. The tide pools along the western shore are best at low tide, so check the NOAA tables before driving out. The third pick is Mission San Diego de Alcalá, the first of California's 21 Spanish missions, founded in 1769 by Junípero Serra. The current structure dates to an 1813 reconstruction. The thick adobe walls hold the interior noticeably cooler than the parking lot outside, and the courtyard garden smells of rosemary and dry California sage. Admission is $7, and the mission sits in Mission Valley about 15 minutes northeast of Balboa Park by car.

Skip SeaWorld on a first visit unless you're traveling with children under 10 who specifically want it. The park (founded 1964) runs $60-90 per ticket depending on the day, and it's a full-day commitment in a part of Mission Bay with nothing else nearby. The honest trade-off on any San Diego trip is time. The city spreads across 372 square miles, and none of the big sights cluster except inside Balboa Park itself. If you have 3 days, spend the first at the park and Zoo, the second at Cabrillo and the Mission, and the third at La Jolla Cove where the water runs about 68°F in August and harbor seals sun themselves at Children's Pool beach. Make the beach day last, when your internal clock has settled.