Down a flight of stairs beneath DOMA's Realm precinct, the light drops and the noise of Macquarie Street disappears. The centrepiece is a cave-like pool sunk into the lower level, ringed by steam rooms and infrared saunas built for slow afternoons. Before your treatment you wait in a Scandi-style lounge with a fireplace, looking out over a courtyard and its water feature. There are nine treatment rooms and a skin suite for the serious stuff. Little National sits above, so you can bathe and then take a lift up to bed. Few Canberra spas commit this fully to going underground. This one earns the descent.