There are a few places in Bali where hiking is very enjoyable.
West Bali National Park.
A hike through the National Park in the western part of the island.
Sunrise in Gunung Batur is another spectacular site, and you should not be surprised if the top of the mountains is a little bit crowded as the sun breaks its nightly sleep.
Gunung Agung is the highest peak in Bali; its top is at over 3,100 meters. Hiking to the top of this mountain is probably the most challenging hike in Bali.