Pixie's Caves is a sloping reef on Ribbon Reef 9½ riddled with crevices, caves and chimneys. Dive the World describes it as a labyrinth of illuminated caves and chimneys dancing in sunlight, and several of the caves are wide enough for divers to swim into. The site lies near Pixie Pinnacle and the other Pixie moorings between Ribbon Reefs No. 9 and 10.

The usual plan is to descend to about 12 m and work down the slope to 25–30 m. The caves are the highlight: shafts of daylight through openings in the reef roof light up the interiors, and swim-throughs connect some of the chambers. Between the caves are patches of staghorn coral and sandy features.

The fauna is mostly small. Shrimp-goby partnerships occupy burrows in the sand, nudibranchs (including the lined Nembrotha) and flatworms crawl across the reef, and coral shrimps and camouflaged coral crabs hide in crevices. Surgeonfish, rabbitfish, damsels, grunts and schools of fusiliers move over the slope. The caves themselves hold sweepers and soldierfish, and the overhangs are good places to find crustaceans with a torch.

Pixie's Caves is a good choice for divers who enjoy structure and light play, and for photographers wanting a change from pinnacles. The caves are open and daylit rather than true overhead environments, but divers should enter only openings with a clear exit and avoid stirring up sand inside. It suits intermediate divers with good buoyancy control. Detailed current descriptions from operators are scarce, so confirm the route and which caves are open with the crew before descending.

Liveaboard only (or fly-dive via Lizard Island). Mike Ball Dive Expeditions' Spoilsport and Spirit of Freedom depart Cairns (Trinity Wharf / Marlin Marina) in the evening and steam north overnight, roughly 12–14 hours and 200–250 km, to reach the Ribbon Reefs by morning; some itineraries fly Cairns–Lizard Island (about one hour, scenic flight along the coast) and board or disembark there. Trips run 3–7 nights and include Pixie's Caves occasionally.

Divers enter by giant stride from the dive deck at the mooring and descend the mooring line. The site is close to the other Pixie moorings; divers descend to around 12 m and work down the slope to the caves.

The Ribbon Reefs sit on the edge of the continental shelf and take the full south-east trade wind from April to October. Lagoon-side moorings stay diveable in 20–25 knot SE winds, but reef-front sites and passes need lighter winds; liveaboards shelter behind the reefs overnight. September to December is usually calmest.

Tidal flow through the gaps between the Ribbons is strong on springs, so exposed pinnacles are timed for slack water. December to April brings rain, lower visibility and cyclone risk; box jellyfish and Irukandji are possible November to May. The caves are best in the middle of the day when sunlight shafts into the chimneys.

Descend to about 12 m and follow the slope down to 20–25 m, looking into the caves and chimneys (enter only those with open daylight exits). Return upslope through the staghorn patches and sand features for the safety stop.

Visited occasionally by Ribbon Reef liveaboards (Mike Ball Dive Expeditions, Spirit of Freedom) as an alternative to the main Pixie sites.