Los Peñasquitos Marsh Natural Preserve and Lagoon is a coastal marsh in San Diego County, California, United States situated at the northern edge of the City of San Diego, forming the natural border with Del Mar, California. The lagoon, previously called The Soledad Lagoon, divides a colony of the endangered Pinus torreyana on a narrow coastal strip. The name "Los Peñasquitos" is Spanish for "The Little Cliffs".