(3,145 M ASL)
A 3142 m high podium is a nice viewpoint and there are at least three options to reach the summit of Merbabu. The three route starts from base camps of Wekas, Selo and Kopeng. The Wekas route is 5~6 km long and starts at an altitude of 1800 m. The trek from Selo is 8~10 km long and starts at an altitude of 1600 m. The Kopeng route is 7-8 km long and it is most difficult. Selo is long but gentle slope. It is also the most beautiful route for day trek.
A good itinerary could be to climb from Wekas in morning, enjoy till evening, camp overnight at Merbabu and get down to Selo, the next morning. The following night, stronger ones can push forward to Merapi from Selo to complete a twin trek.
however, merbabu can be climbed in one day without the need to spend the night in tents. but it takes an experienced guide to assist you in this regard.
reference : tripadvisor.com