Pick one category for the following text. The options are - company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work. Lake Chala - Lake Chala is a crater lake in a caldera on the borders of Tanzania and Kenya on the eastern edge of Mount Kilimanjaro not far from the town of Moshi and 8 km north of Taveta. Depending on the time of year it ranges in colour from deep blue to turquoise and green it is surrounded by a 100 metres high crater rim. The lake is fed by groundwater flows which come from Mount Kilimanjaro fed and drained under ground with a rate of about 10 million m / year. Even the Chala loses volume.
Natural Place