An active volcano which last erupted in 1983 obliterating the surrounding vegetation. It has returned but not to any great extent and no-one is sure when the volcano might erupt again. 

A typical itinerary for trekking Lengai includes a 5-day or 14-day Ngorongoro Highland walk and culminates with the midnight ascent to Oldoinyo Lengai. It is possible to climb Lengai without the highland walk as well, however the combination with the highland walk makes the trek even more special.

Day 1:    Drive to Nainokanoka, Picnic lunch en route.
              Overnight at Nainokanoka

Day 2:    After breakfast walk to Embulbul, Picnic lunch on the way.
              Overnight at Naiyobi campsite

Day 3:    Proceed to Empakaai crater, Picnic lunch on the way.
              Overnight at Empakaai plain campsite

Day 4:    Walking to Mt Oldoinyo Lengai, Picnic lunch on the way.
              Overnight at Mt. Oldoinyo Lengai campsite 

Day 5:    Transfer back to Moshi or Arusha, with picnic lunch.