The Mermaid Series, with runs across the San Diego, the East Bay, and San Francisco, strives to build a community that inspires women to realize their full potential and achieve a heathy lifestyle. And when it comes to inspiration, it's hard to beat the stellar views of the San Francisco edition of the Mermaid Run. Derring-do distance runners can take on the Sirena10 Mile course, which departs from Little Marina Green and treks along the Presidio Promenade/Bay Trail before sending the fleet footed across the Golden Gate Bridge and back. The flat and fast 5K and 10K tracks are packed with scenery, too, with a course around Crissy Field that encompasses the bay, the bridge, and the skyline. All runners, AKA "mermaids," receive a snazzy race shirt, a finisher necklace, and a post-race nosh to refuel their exhausted flippers.