This image by Natalie Hume was chosen for the cover of the new OS Explorer OL23 map of Cadair Idris & Bala Lake, and shows Llyn Cau sparking in the sunlight
Llyn Cau is just one of a number of small lakes scattered around Cadair Idris in Snowdonia. The mountains' name means "Idris's Chair" - "Idris" is thought to either be the name of a mythical giant or a 7th-century prince - who may have actually been the same person. Wild campers have to be careful on this mountain, as legend says if you sleep on the slopes you will wake up as either a madman or, even worse, a poet. It's also supposed to be haunted by Gwyn ap Nudd and his Cŵn Annwn, or spectral hounds, who will round up your soul to the underworld.
Natalie can often be found on top of a mountain in Wales, and you will find more spectacular landscapes and adorable dogs on her Instagram feed. If you would like to see one of your photos on the cover of our maps, there are a couple of days left to enter the current Photofit Competition. You can also submit it for future OS Wallpaper - see the full submission guidelines here.
Universal Mobile Wallpaper: Should work for most mobile devices. For Android devices will show more of the image as you swipe between screens.
To save the image on a computer, right-click (or alt-click) and select 'save target as' or the equivalent for your browser. For most computers, right click the desktop and select 'set wallpaper' to change the wallpaper image. For iOS devices, select the image, press and hold on the image to 'save image', then go to Photos > Share > Set as Wallpaper. On Android devices, select the image, long press to 'download image' and then go to Wallpapers > My photos and select the image.