San Diego more than surf, sand

The home of SeaWorld and a world-famous zoo offers plenty of cash-burning attractions, but San Diego also has awe-inspiring sites that are as free as the sea breeze and go beyond just sunbathing at the beach.

The nation’s eighth-largest city has matured from its “Fast Times at Ridgemont High” surf days. Today it boasts a burgeoning international art scene, thriving farm-to-table food movement, and a booming bio-tech industry.

Here are five free things to do and see in the city and its surrounding areas that run the gamut from botany to border history.

Balboa Park

Balboa Park will be marking its 100th anniversary in 2015 with a host of festivities, although any day is worth a visit to the 1,200-acre urban oasis that rivals New York’s Central Park and is home to the San Diego Zoo.

With 350 species of plants, Balboa Park offers hikes through palm-lined canyons and specialty gardens that are free to visit. balboapark.org/in-the-park .

University of California

On a mesa above the Pacific, the setting alone is reason enough to visit the UC San Diego campus.

The university’s grounds are also dotted by 18 internationally acclaimed art pieces. The most recently acquired installation is Fallen Star by Korean artist Do Ho Suh. The quaint one-room cottage hangs precariously off the seventh story of the engineering school. It is free and open on Tuesdays and Thursdays for anyone who wants to go inside for a serious case of vertigo.

A self-guided tour map is available at stuartcollection.ucsd.edu/map/ .

The Salk Institute

Just west of the UC San Diego campus is The Salk Institute for Biological Studies, which offers free guided tours Monday-Friday.

Established in the 1960s by Dr. Jonas Salk, who developed the polio vaccine, the research facility was designed by architect Louis I. Kahn.

The American Institute of Architects has included the facility among some 30 buildings that it said have “changed modern life.” Reservations are required for the tour atsalk.edu/about/architecture — tours.html.

Border Field State Park

San Diego is a border city but it often does not feel like one despite the fact its center is less than a 20-minute drive to Mexico.

The best way to see the border without crossing it is at Border Field State Park, which is at the farthest southwest corner of the United States. The park is free for those who hike in from the parking lot before the main gate. It’s about a 1½ miles to the picnic area, where visitors can see the towering steel fence marking the border, which plunges into the Pacific.

The U.S. side is an uninterrupted natural coastal stretch that is part of an estuary reserve with more than 370 species of birds. Swimming here is not recommended because of rip currents; parks.ca.gov/?page—id=664 .

Torrey Pines Glider Port

For spectacular sky gazing, head to Torrey Pines Glider Port, a city-owned, private-use glider airport where paragliders and hang gliders jump off the wind-swept bluffs and silently float over the ocean.

The glider port offers lessons and equipment rental, and sandwiches at the Cliff Hanger Cafe.

Anyone can visit for free; sandiegofreeflight.com/jm170/ .