It has a very nice climate, lovely beaches and parks, and many other attractions participants will be able to enjoy (museum-filled Balboa Park, hip Hillcrest, historic Gaslamp, NL West champs San Diego Padres, fauna at the zoo/wild animal park/aquarium/SeaWorld).
A view of the San Diego skyline, with harbor in the foreground and mountains in the background, can be seen below.
A picture taken by the 2023 REU group of a participant enjoying himself at Adobe falls:
A picture taken by the 2007 REUT group of two participants enjoying themselves at Coronado beach: