Batiquitos Lagoon in Carlsbad's Aviara district is a 610-acre tidal-wetland ecological reserve owned and managed by the California Department of Fish and Wildlife, with trail access off Gabbiano Lane south of Batiquitos Drive. The 3.4-mile out-and-back north-shore trail gains just 32 feet of elevation across hard-packed dirt, making it one of the flattest nature walks in North County — a terrain profile that contrasts with the volcanic-rock scrambles at Lake Calavera Preserve on Carlsbad's eastern boundary. Roughly 185 documented bird species use the lagoon, including federally listed Snowy Plover, California Least Tern, and Ridgway's Rail, and the Batiquitos Lagoon Foundation operates a staffed nature center at 7380 Gabbiano Lane with QR-code interpretive signage, docent-led walks, and self-guided trail maps. A mid-1990s restoration project — a joint effort between the City of Carlsbad and the Port of Los Angeles — restored tidal access to the lagoon to tidal flushing, re-establishing saltwater circulation that now supports more than 65 observed fish species. Trail runners and birders who cover this segment of the Aviara coastline also frequent the loop trails at Aviara Community Park less than a mile north on Aviara Parkway. Fishing with a valid CDFW license is restricted to the rock jetties at the lagoon mouth under the Interstate 5 and Carlsbad Boulevard bridges, and leashed dogs are permitted on all trail sections.