Protecting more than 300 acres of coastal habitats along the meandering, estuarine San Pablo River, Castaway Island Preserve is a breezy spot to get away from the city neighborhoods and enjoy a breath of fresh air outdoors. A peninsula on the edge of suburbia, it’s its own world once you pass through the gates. Ibis and wood storks comb through the shallow marsh edges. Gopher tortoises lumber through the protected pine flatwoods of the island, which is surrounded by the estuary. This is a gentle mile-long walk for all ages, well-interpreted and fun to follow – especially for kids – with plenty of benches and overlooks along the way.
Location: Jacksonville / San Pablo
Length: 0.9 mile
Fees / Permits: none
Bug factor: low to moderate
Restroom: at the parking area
This passive park also has a bike trail running from its entrance (connecting to a greater network of bike trails) to the restrooms / nature center complex. At the end of the boardwalk at the end of the park road, there is a place to launch your kayak or canoe to explore the estuary. Picnic tables with grills are around the nature center.
Directions & Map
From downtown Jacksonville, follow US 90 (Beach Blvd) 14 miles east towards Jacksonville Beach. Turn north on CR 10 / San Pablo Road. Continue about a half mile north to the park entrance on the right. Drive in along the entrance road and park your car just past the nature center.
The cedar were in berry and the tang of sea in the air at Castaway Island Preserve as I took this lunch break in my travels to explore the preserve. To find the trailhead, walk down from the parking area near the nature center, following the sidewalk, towards the loop at the end of the road. As you stroll along, there are good views of the estuary, and it’s obvious from here that the island IS an island. Passing a water fountain, you arrive at the trailhead, where there’s a sign that says “Island Trail.” Cross the small bridge over a tidal creek dense with salt hay, and stop to take a look at the map and interpretive information about the preserve. Mind you, there’s no worry about getting lost here, since the trail is concrete or boardwalk, depending on where you are, and the marshes surround the island.
Animal tracks painted on the concrete sidewalk into the woods lead from interpretive marker to interpretive marker, making it fun for small children to follow along. The trail is flanked by wax myrtle and Florida myrtle, which bursts forth in fluffly puffs of butterfly-attracting blooms each fall. Loblolly pines tower overhead and create a small but dense forest on the island. After a quarter mile, you encounter a bench at the Wood Stork marker. Off to the left, a well-beaten unpaved trail slips over to the edge of the island for a closer look at the estuary’s edge. Bracken fern and grapevines grow luxuriously in the understory along this path.
Returning to the main trail, you quickly discover another side trail off to the right. This leads to a substantial boardwalk that is a highlight of the trail system. Turn right. The boardwalk is surprisingly long and straight, rising above the estuary. You can see the variations in the landscape below; salt hay creeps in and forms small meadows that undoubtedly are damp, whereas on the high spots, cedars and Florida myrtle take over. Needlerush pokes out from low spots where water collects. Some of the topless cabbage palms have large holes drilled in their trunks, undoubtedly by woodpeckers. The boardwalk crosses a tidal creek, where the water is barely in evidence amid the thick vegetation. Off to your left, another boardwalk extends off this main trail. On the right are mounds that follow the creek’s edge. Could it be that, like the Calusa, the Timucua dug canals along the estuary for fishing? Despite the great interpretive information about the habitats, I don’t find an answer to my question.
Continue along the main boardwalk and make a left. This short extension jogs up to an observation deck overlooking the Intracoastal waterway, which historically was known as the San Pablo River. It was the barrier that kept settlers in Jacksonville from crossing over en masse to the barrier island and beach until the river was bridged by the Jacksonville and Atlantic Railway in the 1880s. You can see homes on the far shore, but they’re mostly tucked into the trees. Keep alert – I was amazed at the amount of wildlife I saw on this short walk. From here, you can look back across the sweep of the island as well. Turn around and head back to the main boardwalk and hang a left. The boardwalk continues a short distance to end at another overlook of the estuary and river.
Head back along the boardwalk to the island. White ibis wing overhead as you continue past red cedar (Juniperus virginiana) so laden with berries that the tips of the trees look like they’re frosted. There’s a constant warble of birdsong from the far pines, more noticable as you approach the island. Rejoining the concrete trail after 0.6 mile, turn right, passing an interpretive sign about opposum. More “social trails” lead through the forest on the left.
Just past the tricolor heron marker is a small Southern magnolia, and the trail forks just beyond it. Keep right. You come up to a bench very quickly. The track that looks like a snake leading along the pavement to this sign is for the Eastern diamondback rattler, a resident we hope we don’t stumble across here. The trail continues its meander with dense thickets of saw palmetto on either side draped in grapevine and love vine. Past the sign for the horned owl, foot prints lead on along the pavement to the last of the interpretive markers – humans in the habitat!
As the trail curves away from the “human being” interpretive marker and its bench, there’s a lot more Florida myrtle along it. You can barely see the estuary to the right, but you know it’s there. At this point, I did nearly stumble across wildlife.I froze in mid-step hearing a hiss in the trail, thinking snake, and instead encountered a rather large gopher tortoise lumbering along the pavement. Overhead, several wood storks glided just over the treetops. The loop ends just around the corner.
From here, continue back on the concrete the way you came and take note of the many wildflowers in the understory – I saw morning glory and carolina jessamine draped over the bushes. On the ramble back, I took the time to read the other interpretive markers, and noticed a couple interesting facts about this preserve. First, despite the 99*F temperatures at noon, the walk was cooled by a good breeze most of the way. Second, despite the nearby proximity of busy US 90 and its bridge over the Intracoastal, the estuary has a dampening effect on traffic noise. I thought it was just my mind, lost in thought, but in transcribing this hike I heard birds and wind in the background, not cars.
After leaving the island by crossing the bridge, you may want to take a peek down the boardwalk at the end of the park road, which provides paddlers a put-in platform and gives you another sweeping view of the estuary. To return to your car, just follow the sidewalk back up along the park road to the nature center.
0.0 parking area
0.2 trail entrance / kiosk
0.3 bench @ wood stork marker
0.3 side trail to boardwalk
0.4 tidal creek
0.5 observation decks
0.6 end of boardwalk
0.6 beginning of loop
0.7 end of loop
0.75 pass the boardwalk trail again
0.8 bridge over tidal creek
1.0 parking area