San Elijo Lagoon is one of the largest remaining coastal wetlands in San Diego County, and the scale of what lives here is genuinely impressive. When you walk the more than seven miles of trails winding through different plant communities, you’re moving through habitat for 300 species of plants, 16 species of reptiles and amphibians, and 26 species of mammals. Your dog will pick up on the activity—the rustling in the salt marsh, the movement in the coastal sage scrub.

The lagoon is especially known for its bird life, with at least 300 species recorded here over the years, including 76 sensitive species. Even if you’re not a serious birder, the sheer number of birds you’ll see and hear makes the place feel alive and active in a way that’s different from typical dog walks.

The “green” nature center on the north side of the lagoon has exhibits explaining the plant and animal communities, the lagoon’s history, and the various natural and human influences shaping this sensitive ecosystem. It’s worth a stop to understand what you’re actually looking at out on the trails. Restrooms and water are available here if you need them, which is helpful since the southern trails have no developed facilities.

The trails themselves vary quite a bit. Some sections are more open and exposed along the water, while others cut through denser vegetation where it’s shadier. The walking is mostly flat and easy, though the paths can get muddy depending on recent rain. In spring and early summer, the wildflowers along the edges of the trails are substantial—lupine, California poppies, and various coastal flowers you don’t see everywhere.

Keep your dog leashed throughout, and pack out what you pack in. The reserve protects a genuinely rare ecosystem, and it shows in how much life you encounter on even a short walk.