As part of the Corpus Christi celebrations, the town of Adeje in Tenerife decorates the streets with ‘carpets’ made from salt along the procession route.
I think the carpets are made using salt tinted with powder paint, which is spread over a big outline of the picture taped to the street.
Between the carpets are plainer stretches with stencilled patterns.
Each carpet is unique and some, though simple, are very effective.
The carpets are, of course, intended to be pristine for the passing of the procession, and only a very few tourists are ignorant enough to walk on them for a better perspective for their snapshots. Pigeons, however, are less respectful.