This is a Grade 4 walk so ideal for the more serious walker. The best starting point is at the Rothiemurchus Camp and Caravan Park at Coylumbridge.  This walk takes you through the pass from Speyside to Deeside and climbs to an altitude of 835 metres. There are some good views to be seen but remember this is wild isolated countryside so make sure you are well prepared. 

You can get a step by step guide to the route here.