Map of Cadair Idris & Bala Lake 1:25,000 scale (4cm to 1 km or 2.5 inches to 1 mile) With this map you will receive a code for use on your iOS or Android smartphone or tablet. Map sheet number OL23 in the OS Explorer map series is the ideal partner for walks and rides around the Cadair Idris and Bala Lake area of Snowdonia National Park. The mountain range of Cadair Idris is popular with hikers and people looking for challenging terrain to explore. Highlights of the area include: Minffordd Path, Talyllyn lake, Llyn Tegid, Dol Idris, and 8 000 year old oak woods. ISBN - Standard version:  9780319242629 Edition - Standard version:  2015-05 Publication Date 01/05/2015