I have climbed Ben Nevis on a view occassions, the last time with my brother and father where the clouds were low and there was a lot of snow on top. On the summit plateau we had to walk on the bearings we were given from the guides office in Fort William, and count our steps as the visibility was poor. This was particularly pertinent of the way back as we were concerned about the cornices. The walk starts at pretty much sea level and is quite a slog. It is not of any technical difficulty and I do not remember there even being a small scramble but you need to be careful on the top in poor weather and not drift off course on your way off the summit.

Definitely a full and tiring day. 5-7 hours