However, the routes described are necessarily limited to well-known paths, such as the Pyg track on Snowdon or the traverse of Kinder Scout in the Peak District, and walkers can vary their routes according to choice or need. The limited scope of his guides is clear from the Wales volume, which has few routes in the Brecon Beacons or Black Mountains for example. The routes in that volume are concentrated in Snowdonia and North Wales, where rock exposure is much greater than in the south or central areas of the country. Notable omissions include the Berwyns or Clwydian hills however, both ranges of mountains to the east of Snowdonia, which have many interesting routes to their summits. Likewise there are no paths described in Shropshire such as the Stiperstones, The Wrekin, Caer Caradoc or the Long Mynd. The Welsh borders is not considered at all.