I have to admit that I’d never even heard of the Hochschwab mountains until this little photo story turned up in the Daily Mail.

At the foot of the mountains, in the Styrian region of Austria, is a basin that leads a schizophrenic life.

In winter, it’s a leafy park popular with hikers.

In summer, as the mountain snows melt, it becomes a unique diving mecca. The park is still lush as ever, with its little bridges and park benches, but suddenly it’s submerged under as much as eight metres of crystal clear mountain water.

It must make for an extraordinary diving experience, but only with a good thick wetsuit. That melted mountain snow has the power to shrink walnuts.

For more pictures, click here.