During the past centuries there were numerous attempts to make Fuerteventura greener again - one of them was the Peñitas Dam. Unfortunately the erosion of the surrounding mountains is too strong, pushing a lot of soil into the dam, making the water completely disappear in the mud. It still contains a lot of water though, given how happy the trees are in the valley - trees, which are already rare at Fuerteventura.
(Also: a small praise for my Pentax camera, for producing an image like this, ouf of the machine without post-processing or filters.)
(Oh, by the way: this entry was written by Peter Molnar, and originally posted on petermolnar dot net.)