Make a stone float in the sea

The stone is pumice, volcanic froth so full of air that it floats. On Lipari's northeast coast, near Porticello, a whole hillside of it runs white straight down into very blue water.

The way there is by boat from Lipari's marina, up the east coast until the hillside turns white. It is the easy afternoon of the week, and nobody climbs anything.

At the slope the boat stops for a swim. Then the trick: a stone picked up from the shore, set on the sea, and it does not sink. At least one usually goes home in somebody's luggage, to float in a bathtub.

Lipari quarried pumice on an industrial scale from the end of the nineteenth century and shipped it around the world. The digging stopped at nearby Acquacalda in 2000 and at Porticello in 2007, a decline that followed the islands' listing as a World Heritage Site in 2000.