Windley Key Fossil Reef Geological State Park

Overview

At Mile Marker 84.9 in Islamorada, this former limestone quarry is an open‑air fossil reef—Key Largo limestone frozen in time. Expect a compact, fascinating stop with quarry walls, preserved machinery, and a small education center. Plan for about 1–2 hours if you walk the trails and read the exhibits.

What You'll See

• Quarry cuts up to eight feet high showing star, brain, and porous corals embedded in the rock.
• Striking red bands of terra rossa—soil enriched by African dust layered into the quarry walls.
• Outdoor displays of historic cutting equipment and numbered interpretive stops along the paths.
• Low hammock forest that attracts birds; iguanas are commonly spotted.

Trails and How to Explore

There are five short, self‑guided trails totaling roughly 1.5 miles. Surfaces are rocky and often pea gravel, so wear closed‑toe shoes or sturdy sandals. Pick up the trail guide to match the numbered posts and make sense of the geology and railroad history as you go.

History & Geology Snapshot

This land of fossilized coral—Key Largo limestone—was quarried to build Henry Flagler’s Overseas Railroad in the early 1900s, then continued producing decorative “Keystone” stone into the 1960s. Walking the cuts is like reading pages of an ancient reef, with coral heads preserved where they grew and those terra rossa streaks telling a long, wind‑borne story.

Logistics

• Address: 84900 Overseas Hwy, Islamorada.
• Hours: 8 a.m.–5 p.m., Thursday–Monday; closed Tuesday–Wednesday.
• Admission: $2.50 per person for self‑guided visits.
• Ranger‑guided tours (seasonal): December–April, Friday–Sunday at 10 a.m. and 2 p.m.; $2 per person.
• Facilities: on‑site parking, air‑conditioned restrooms, water‑bottle filler, picnic tables, and a visitor center with exhibits.

Wildlife

Bring binoculars if you bird: the hammock edges can produce nice looks at resident species. Enjoy iguanas from a distance—no feeding or touching.

Best Time to Visit

Go in the morning for cooler temps and softer light on the quarry walls. If you’re after a guided experience, time your visit to the 10 a.m. or 2 p.m. tours during the December–April season. Midday can feel extra hot as the bright limestone reflects the sun, so carry water and sunscreen.