Tide pools near Delray Beach

Gulfstream Park

The closest exposed rock to Delray Beach, a few minutes up A1A in the town of Gulf Stream. Florida Atlantic University's geologists map the Anastasia limestone here running about four tenths of a mile along the shore, with a notched cliff face, sea caves that have since filled with cement, and burrowed rock surfaces. Otherwise it is an ordinary county beach park with a playground, picnic grills, restrooms and outdoor showers, so it works as a quick low-tide stop rather than a day out. The outcrops sit south of the park itself, so you walk down the beach to reach them.

South Beach Park

Boca Raton's southernmost beach park, where the Anastasia outcrop runs about three tenths of a mile south from the parking area with smaller ledges sitting out in the surf zone. FAU's geologists record solution pits and heavy burrowing in the rock here, the same formation that surfaces up and down this stretch of coast. The catch is the price: Boca charges non-permit holders a flat daily rate to park, which on a weekend makes this by far the most expensive stop on this list. Lifeguards are on duty year round, which is not true of most of the rocky beaches further north.

Ocean Reef Park

A Singer Island county park and probably the best free tide pooling in the West Palm Beach area. FAU's geologists describe both a beach outcrop and an offshore reef that is exposed at low tide, with low cliffs running about four tenths of a mile and solution holes that hold water as the tide drops. The park has a playground, grills, restrooms, outdoor showers and a beach surf wheelchair you can arrange through the lifeguards. Rock masses that have collapsed from the cliffs sit in the surf zone, so bring shoes you do not mind soaking.

John D. MacArthur Beach State Park

The only state park in Palm Beach County, reached by a 1,600 foot boardwalk across an estuary. Reef and rock outcroppings lie in shallow water right off the beach, and snorkelers there regularly see reef squid, tropical fish and schools of tarpon and snook. There are no lifeguards and a small per-vehicle entrance fee, so it suits confident swimmers and families who plan to stay in the shallows. A nature center, kayak and paddleboard rentals and a tram from the parking lot make this the easiest one on the list to turn into a full day.

Coral Cove Park

Known locally as Little Blowing Rocks, and it earns the name: a compact Anastasia limestone outcrop runs south from the boardwalk with notched cliffs, small caves, a double sea arch and pools left in the rock as the tide drops. Only 600 feet of the oceanfront is open for swimming, and that is precisely because of the rock formations, so the guarded stretch and the interesting stretch are different places. Entry and parking are free and there is a playground, restrooms and outdoor showers. Living worm reefs grow on parts of the rock face, so walk on sand rather than on the rock itself.

Blowing Rocks Preserve

The dramatic one. The Nature Conservancy protects the largest Anastasia limestone shoreline on the Atlantic coast here, and when the sea is rough at high tide the blowholes throw spray up to fifty feet. At low tide the same solution pipes and crevices become the pools, and shorebirds work the exposed rock for food. It keeps short hours, locks its gates at 4:30, has no lifeguard, and asks an optional two dollar donation. Parking is free but limited and often full by late morning on weekends and holidays, with the nearest overflow a mile south at Coral Cove Park.

Bathtub Reef Beach

A different kind of rock. Instead of limestone, a reef built by tiny tube-building Sabellariid worms sits just offshore and breaks the swell, leaving the calm shallow lagoon that gives the beach its name. That makes it the gentlest of these for small children and one of the most popular snorkeling spots on the Treasure Coast. The reef is fragile and the beach erodes badly in winter storms and hurricanes, so Martin County closes and renourishes it periodically; check conditions before making the drive. Lifeguards are on duty daily and parking is free.

House of Refuge at Gilbert's Bar

The rock is the headline here. FAU's geologists trace the Anastasia outcrop two miles along the shore from just north of Bathtub Reef, with cliffs up to fifteen feet, notches, caves and abrasion platforms along the cliff bases that are covered in sand except at low tide. Above it stands the last surviving House of Refuge in Florida, the oldest building in Martin County, recently reopened after an extensive restoration. The rocks, the beach and the view from outside cost nothing and there is limited free parking, so the ticket price only matters if you want to go inside. The Georges Valentine shipwreck lies about 100 yards offshore in shallow water and can be snorkeled from the rocks.