Lonely Planet review
The most interesting sight near town is a 20-minute walk, signposted from the Bukit Lawang Eco Lodge, to a bat cave. This 2km walk passes through rubber plantations and patches of forest. A lot of the trees are durian, so take care in late June and July, when the spiked fruits crash to the ground (there are signs warning people not to linger). You'll need a torch (flashlight) to explore the cave.