After two nights at Lake Manyara, we drove to the Ngorongoro Crater.  Here is a photo of a model of the crater area.  It is the world's largest unbroken caldera, and the floor is 610m (1,800ft) below the rim, and it covers about 260km² (100 sq. miles).  The crater floor is about 1,700m (5,600ft) above the sea level.  Animals in the crate are pretty much "trapped" and do not migrate. Although it was actually raining on the crater rim early in the morning, it eventually cleared up,  and once we descended into the crater, it was dry and sunny.

If you have a broadband connection, here is a short video clip (41 secconds) you might want to view.

Today is Day 5 in Tanzania, and we leave the crater for the Serengeti Plain toward Central Serengeti.  On the way we make brief stops at a Maasai Village just outside of the crater and a museum at Olduvai Gorge, an important archeological site.