I highly recommend to anyone traveling in Tanzania - especially in the Kilimanjaro area - to spend some time exploring villages at lower elevations on Kilimajaro. Once you get near the national park entrance, the climate changes completely from the base. Waterfalls, fruit trees, and stunning views are all around.
You will probably feel you are having even more of an "adventure" than when you're actually climbing! The trails are often packed with tourists but the small villages at the base of the mountain, once you get away from the tourist routes, feel very remote. If you're taking the Machame or Maua route, make a left at Marangu Mtoni instead of a right towards the gate. Ride the road until the final dala-dala station and then just start asking the locals where the good views, waterfalls, and farms are. You'll be amazed what you'll find, and you may just be the only foreigner out there.
This picture is from Mkyashi village. Grab a local beer and a local meal and get an authentic, off-the-path experience.
Also be sure to ask about the local nuns' convent in Maua. It's completely self-sustaining in terms of both food and electricity, and the nuns will make sure you leave with a full belly! You can even stay the night in a comfortable room if you'd like.