Cultural centers form an important element of Balboa Park [1]. The Japanese Friendship Garden (2125 Park Blvd., 619/232-2721, www.niwa.org [2], Tues.–Sun. 10 a.m.–4 p.m.) began as a teahouse during the 1915–1916 Exposition, and grew over the years to include many elements of a traditional Japanese formal garden.
You can enjoy the tranquility of the Zen garden, koi pond, and wisteria arbor, or take tea and sushi at the Tea Pavilion. This is the perfect place to enjoy a quiet walk hand-in-hand with your sweetie.
For variety, the garden displays temporary exhibitions that mesh with the Japanese cultural traditions exemplified here.
Check the website for one-day classes in Japanese arts, usually held on weekends.
Links:
[1] http://www.moon.com/destinations/california/san-diego/sights/balboa-park-and-hillcrest
[2] http://www.niwa.org