Thousands of sites exist where it is possible to collect natural coloured sands for craftwork, with an enormous range of colours being available around the globe varying with the contents of the mineral charged waters leaching through the sands. But for the tourist the vertical sand cliffs at Alum Bay on the Isle of Wight form the central portion of a visual geological phenomenon (best viewed after a shower of rain) which encapsulates the impressive chalk spires of The Needles and Tennyson Downs. Although tourists are no longer encouraged to obtain their own sand from the cliffs, numerous companies on the Island sell sand for the purpose of Sandpainting.