How about this for 'Natural', but totally 100% manmade - and just like 'PROJECT 1999 - SUFFOLK', created in very difficult circumstances where the power of nature had to be accommodated; again due to a very, very high water table. Hence the very mature Weeping Willow thriving in the boggy ground.

SO, IF A NATURAL POOL IS WHAT YOU WANT - go to 'DIY'.