What are natural swimming pools? Originating in Austria, self-cleaning natural swimming pools use plants as a living filtration system – much like a pond. The plants filter out contaminants from the water, keeping it crystal clear and free from algae. You’ll feel almost as if you were swimming in the wild! How do they work? The pool is split equally into a regeneration zone (with oxygenating plants in a deep gravel bed) and a swimming area (plant-free open water). A pump is used to circulate clean water back into the swimming area after it has been drawn through perforated pipes beneath the gravel. A submerged wall divides the two zones to stop swimmers’ legs from becoming tangled in weed, and the floor is lined to make it feel like a normal pool underfoot. How do you look after them? The aim is to keep the water biologically balanced and devoid of nutrients; so do not add fish, and  discourage ducks from swimming in it (a starter pistol fired in the air, or a dog, helps with this!). It’s also important to scoop out any leaves and cut back reeds in autumn using a skimmer, a creature- friendly device that floats on the open water and collects debris. What are the benefits? Unlike conventional pools, there’s no need for chlorine, so water is soft on the skin. The planted area is a sanctuary for wildlife such as water beetles, newts and dragonflies. Plus, the shallower water in the planted regeneration zone warms quickly and feeds in to the swimming area, so you can use it for most of the year. These pools are low maintenance because they never need to be drained and, in winter, can be left to ice over. How much do they cost? It varies depending on the size of the pool and the features selected (you can add on a floating deck, jetty or stepping stones), but roughly £50,000 or more.

Wildlife sanctuary Designed by Chris Carr Associates (01266 286256), an oak-and-slate pavilion provides the perfect haven from which to watch wildlife following a swim in this natural pool in Suffolk. A green oak jetty, pebble edging and clusters of tall reeds – all part of the vision of The Swimming Pond Company (theswimmingpondcompany.com) – blend the pool with its surroundings and enhance the tranquil feel of the scene.