You can walk through the tunnel to the other side of the Napier Range. The trek runs underground for 750m and you have to wade through several permanent pools and return the same way. At least five species of bats live in the cave, including ghost bats and fruit bats, and stalactites descend from the roof in many places. The roof has collapsed through to the top of the range near the centre of the tunnel. Take a torch, wear sneakers and be prepared to get wet and possibly cold. Day trips to Dimalurru (Tunnel Creek) operate from Derby, Fitzroy Crossing and Broome and usually include a visit to Bandilngan Windjana Gorge. You need a four-wheel-drive to access the park, which is generally inaccessible during the wet season.