A relief map hanging in the lobby of the Ndutu Safari Lodge shows the area well also:
We left Rhotia Valley and passed not too far from Lake Manyara as we approached the entrance to the crater National Park. This is probably a good place to bring in Ernest Hemingway for his 1935 description of the area:
It was a green, pleasant country, with hills below the forest that grew thick on the side of a mountain, and it was cut by the valleys of several watercourses that came down out of the thick timber on the mountain. Fingers of the forest came down onto the heads of some of the slopes and it was there, at the forest edge, that we watched for rhino to come out. If you looked away from the forest and the mountain side you could follow the watercourses and the hilly slope of the land down until the land flattened and the grass was brown and burned and, away, across a long sweep of country, was the brown Rift Valley and the shine of Lake Manyara.We never paused above Lake Manyara on the way up the mountain. I'd make that a mandatory stop on any trip that I planned. But later, and not too far away, I did get a halfway decent shot of the countryside looking toward the south.
... There was a cool breeze from the east and it blew the grass in waves on the hillsides. There were many large white clouds and the tall trees of the forest on the mountain side grew so closely and were so foliaged that it looked as though you could walk on their tops. Behind this mountain there was a gap and then another mountain and the far mountain was dark blue with forest in the distance.
Hemingway, Ernest (2002-07-25). Green Hills of Africa (p. 49-50). Simon & Schuster, Inc.. Kindle Edition.
The entrance to the National Park (and UNESCO World Heritage Site) is marked by a gate and rest facilities. The main building also features a number of exhibits about the geology and geography of the area.
And, if you stand at the edge of the building and look out toward the south, you will see the green canopy of foliage that Hemingway described above.