The azure pool only appears after heavy rains, but cold, wet weather hasn’t deterred locals from taking a dip

On kunanyi/Mount Wellington, 200mm of rainfall has transformed a rocky patch of forest into a striking pool. It’s freezing cold, but the water is clear and blue.

The Disappearing Tarn appears only after a heavy downpour. It’s shrouded in a layer of mystery among visitors and scientists alike: geomorphologist Kevin Kiernan speculates its arresting blue colour may be a result of fine sediments in the water as it pools over depressions in the land. At the bottom of this basin, organic matter rots and occasionally releases bubbles.