Ben Nevis Ridges + Ski
In June of 2015 Tim Gomersall completed a solo round of the four Nevis ridges linked by ski descents. This included Castle ridge, Tower ridge, Observatory ridge and North East Buttress with ski descents of Number 3 gully, Tower gully and Coire Leis. Starting at 4:30 from the CIC hut with a hut to hut time of 6 hours.
Full writeup here