Mount Meru is an active (but dormant) volcano located north of Arusha in Tanzania.
At 4562 metres it is Tanzania's second highest mountain and the fourth highest mountain in Africa.
The mountain became well known mainly because it is only 70 km from Mount Kilimanjaro.
Mt. Meru has become a popular "warm up" trek for Kilimanjaro climbers.
Most importantly, at a height of 4562 metres (14967 feet) Mt. Meru requires your body to make changes to adapt to the altitude.
It's called acclimatisation and as a result you will be much better prepared for you Kilimanjaro climb. That altitude acclimatisation is the main reason why people climb Mount Meru and Kilimanjaro together.