Webdiscover san diego's hidden gems with our guide to the city's most fascinating flea markets and thrift stores. Webhaving been to countless flea markets in san diego, i can confidently say that i have explored some hidden gems. From vintage treasures to unique handmade. Webdiscover secret swings, sea caves, nude beaches, and more in this guide to the best hidden spots in san diego. Learn how to find them, what to expect, and why. Here are 10 top picks, from la jolla’s secret swings to torrey pines.