As many people describe Batur in Agung's reviews.
Mount Batur reaches 1700m, it overlooks Batur Lake (1400m). The climb is an easy morning walk, only 300 elevation difference. A good way to start the day, walking with pets and children. Very crowded for sunrise.
Mount Agung is the highest peak of Bali, 3031m. It is officially closed but you can easily climb it, by yourself or hiring a guide (which I recommend). There are 2 ways:
-the "short way" from Pura Pasa agung, you start at 1700m and go to the top crater.
-the "longer" way, from Besakhi at 1000m up to the summit (see pictures I took this morning, January 2020).
This 2nd option is short (8 km) but steep (over 2000m elevation). Basically you start at midnight to arrive before 6 am, for sunrise. You need an average fitness. It requires carefulness, and some equipments: front lights, good shoes and a jacket.
Be aware that descending the higher, rocky part is the most difficult. It's slippery and some stones may fall: remain
Overall it's a great experience. The sunrise colors and the view is the best reward.