Green Cove Spring is a 3rd magnitude spring on the west bank of the St. Johns River. A 2-foot-high concrete railing with a diameter of about 15 feet encircles the main vent of the spring pool. The pool tapers downward in soft marl like an irregularly shaped funnel to a 2-foot diameter cavern opening in its bottom, approximately 30 feet below the pool surface. The 2-foot vent then opens into a cavern 25 feet wide, trending in a northeast direction toward the St. Johns River. The roof of the cavern descends to a depth of 50 feet, and the bottom of the cavern falls to 150 feet. Some of the flow in this cavern is toward the St. Johns River, and it is possible that the spring discharges water into the riverbed (Rosenau et al. 1977). Discharge from the spring pool is through a 4-foot-wide weir opening on its northeast side to a 50-foot by 100-foot swimming pool. The swimming pool overflows through a weir on its east end to a spring run that flows about 450 feet eastward to the St. Johns River. Some or all of the flow from the spring can be directed from a flume to bypass the swimming pool. The spring is part of a city-owned park and recreation area, with picnic tables, benches, walkways, and shade trees.
Green Cove Spring is located within a city park and is a popular swimming area. No swimming is allowed in the actual spring. Water from the spring directly supplies the water for the swimming pool. In the 19th century, the spring was a popular health spa.