starting at deep and becoming as shallow as . The tunnel extends outside Peacock Spring State Park to Challenge Sink. Challenge Sink Challenge is an inline sink, the northernmost sinkhole in the system, and is the only sinkhole outside of the Peacock Springs State Park. Steep sides make entering and exiting Challenge difficult. It is a popular destination for divers entering Upper Orange Grove. Cisteen Sink Cisteen is a large offset sink like Orange Grove. It offers a very small, silty entrance to the cave system, and is usually covered in a thick layer of duckweed. Peacock III Peacock III is a siphon, meaning it takes in water rather than discharging it, as a spring would. Peacock III has a separate system from Peacock I, II, and its related sinks. The system is very low, silty, and shallow, except for one room, Henley's Castle, which drops to depths of over . Waterhole Waterhole is another offset sink. It contains geological features not seen in the rest of the system, such as low bedding planes, as opposed to the vaulted ceilings found in the rest of the system. Gallery References External links Wes Skiles Peacock Springs State Park at Florida State Parks Peacock Springs State Recreation Area at Absolutely Florida Maps of the cave system Parks in Suwannee County, Florida State parks of Florida Caves of Florida Landforms of Suwannee County, Florida Bodies of water of Suwannee County, Florida Springs of Florida