The gold is real and it is not mineral: the ceiling glitters because light is reflecting off water droplets beaded up on a coating on the rock. Getting there involves a ladder and a piece of rock the park itself calls headache rock, so mind your skull on the way in and out. The downstream half, heading north, means stooping. The back section around the dome is a figure-8, and people do go round it twice without noticing, so keep track of where you are.
Other places on the map within a couple of hours.
