Manicured Marco Island is known for its beautiful beach, which is lined with resorts, condos and mansions. The exception to all this commercial development is a gorgeous, wild section of Tigertail Beach.

There’s a reason the beach is so unspoiled: 10 years ago it was an offshore sand bar called Sand Dollar Island. In 2005, however, Hurricane Wilma dumped sand at the southern end, connecting it to the mainland, and this stretch of land became Sand Dollar Spit.

You can reach the beach on the spit by walking north from the main beach, but it’s a long walk and many people take a short-cut and wade across a shallow lagoon to reach the beach.

The squeamish may squeal at the oozy lagoon bottom, but there’s a big payoff on the other side — three miles of beach with soft white sand, scads of shells, ospreys squealing overhead and so many shore birds that it’s a stop on the Great Florida Birding Trail.

Tigertail Beach is a Collier County park, and thus not widely known outside the region. In addition to having an impressive wild beach, Tigertail also has first-rate amenities. After you pay $8 to park, you come to a clean and well-kept park with changing rooms, a snack bar, a great playground and a concession stand that rents kayaks, stand-up paddleboards and other beach gear. This developed part of the park faces a saltwater lagoon. Across the lagoon, on Sand Dollar Spit, you leave development behind.

The lagoon is about 50 yards across and at high tide, the water comes up to waist or chest high at a buoy that marks the cross-over path. The bottom of the lagoon is squishy, grassy mud. You don’t sink, but you do have to overcome the “yuck” factor as you wade through murky water.

Your reward, though, is a stunning vista of blinding white sand and blue-green water. As you walk miles out on the sand spit, you leave most people behind. You might feel like Robinson Crusoe if it weren’t for the Marco Island highrises in the distance.

The beach has some of the best shell collecting in Southwest Florida. Be sure to watch for wildlife too. Adjacent to the park is Big Marco Pass Critical Wildlife Area, a resting site for a variety of migratory shorebirds. Three species — black skimmers, snowy plovers and least terns — nest and raise their young in the protected area of Tigertail and Sand Dollar Spit.

? Tigertail Beach, 490 Hernando Dr., Marco Island; 239-252-4000;www.colliergov.net/Index.aspx?page=468. Hours: 8 a.m. to sundown.

Directions: There is no sign for the turn off the main road. From North Collier Boulevard/State Highway 951, go north on Kendall Drive. This will take you through a residential neighborhood. Turn left at Hernando Drive, where there is a sign directing you to Tigertail Beach. Hernando dead-ends into the park.