One Day in Nairobi

Dear Nairobi forum members,

I will be in Nairobi with work and will have just one day of free time. What would be your most recommended thing(s) to do during this limited time? I'd love to be able to get the most of nature and culture. Thanx in advance and please feel free to recommend me do's and don't's that might be unknown to someone from the outside.

All the best,
Asli