You want great scenery, peaceful environs and a little light adventure. My recommendation: Sarangot Hilltop Hotel where you can view Mount Everest on a good day, as it is situated on a hilltop, it is really peaceful as it is off the tourist sites. Very mild trekking can be done on the various trails around the hotel where you can see small waterfalls, numerous song-birds, some wild animals if you are lucky, and bracing temperatures.
See some views of the hotel here:
http://images.search.yahoo.com/search/images;_ylt=A2KJkIajcVROElQAAiuJzbkF?p=Sarangot+hotel+in+Kathmandu%2C+Nepal&fr=ipad&ei=utf-8&n=30&x=wrt&y=Search about 7 years ago