There is free on-street parking south of the institute on 6th Avenue.
Also south of the institute, there is free parking on an access road in Balboa Park that parallels 6th Avenue (this is about 5 blocks south). The access road is called Balboa Drive. Once you drive past the institute, you’ll come to a light at Upas Street. At the light, make the TOP left turn onto Balboa.
Our neighborhood is set up as a grid. To the west of 6th Avenue are residential streets: 1st, 2nd, and 3rd Avenues have free parking. (The walk from 1st Avenue is only 12 or 15 minutes.)
Lastly, be aware that if you park at a meter, you will have two hours. The attendants are very vigilant.