Darjeeling
My first full day in Darjeeling was spent almost entirely in or near my hotel room. I got up and had breakfast, and feeling tired, I went back to bed. I subsequently felt increasingly ill. The stomach pains eventually started subsiding with every quick dash to the bathroom, but it took a few days to properly recover.
Darjeeling's a great place, however. I could see Kangchenjunga, third highest mountain in the world from my hotel room, with the light changing throughout the day. I basically relaxed for 5 nights, and didn't do much. The Himalayan Mountaineering Institute, with its memorials to Sherpa Tenzing Norgay, and the ropeway cable-car which descended over steep tea plantations were both well worthwhile.