Gotham City is a sloping reef between Ribbon Reefs No. 9 and 10, beside Challenger Bay, and it holds one of the largest Pavona clavus colonies on the Great Barrier Reef. Column coral forms great stands of pillars, and here the colony climbs from about 30 m to 5 m, creating a skyline of grey-brown towers that gives the site its name.

Mike Ball describes it as a sloping reef rich with hard and soft corals that becomes exciting at night with hunting sharks and trevally. Much of the surrounding reef was damaged by the 2014–15 cyclones, so the Pavona colony is the architectural centrepiece. It is also a habitat in its own right: leafy scorpionfish, lionfish, anthias and clouds of damselfish crowd the columns, and batfish hover over the top.

The surrounding slope carries red bass schools, giant trevally, surgeonfish, milkfish, diagonal-banded and giant sweetlips, fusiliers, barramundi cod, flowery cod, Malabar and Queensland groupers, starry pufferfish, bumphead parrotfish and barracuda. Whitetips rest on the sand and grey reef sharks patrol deeper. In summer manta rays visit cleaning stations on the eastern side. Around dusk, mandarinfish emerge from rubble; Mike Ball's photographers' guide suggests looking pre-sunset or in poor light. Nudibranchs, including Notodoris minor and several Chromodoris, are common.

As a night dive, Gotham City delivers the same torch-hunting behaviour as Challenger Bay. By day it is an easy, relaxing dive suitable for all levels, with plenty to keep macro and wide-angle photographers occupied. Combine it with Challenger Bay on the same mooring for a day-and-night pair of dives.

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 Gotham City, often as a night dive.

Divers enter by giant stride from the dive deck at the mooring and descend the mooring line. It shares a mooring area with Challenger Bay, and Mike Ball commonly schedules it as the evening dive.

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. Like Challenger Bay, Gotham City is on the sheltered side of the reefs and is usually diveable in moderate trades.

Descend to the base of the Pavona clavus colony at 25–30 m and work slowly up its 30 m length, checking the columns for leafy scorpionfish and lionfish. Cross the sloping reef toward the rubble areas at dusk for mandarinfish, then ascend over the slope for a safety stop at 5 m.

Mike Ball Dive Expeditions (Spoilsport) – regular on Ribbon Reef, Coral Sea and minke itineraries, often at night.