Gunung Api (translation fire mountain) is a 666m high active volcano in Indonesia's Banda Islands.
To access the start of the trail leading to the top, speak with any of the local fishermen in the main port of Banda Naira, who will often gladly zip you over the straight. Expect to pay them a little for their effort, maybe 30k rupiah.

The trail itself is easy to follow once you get to it although it can be rough in places, with lots of roots and washouts after storms. It climbs steeply for most of the hike, and with the heat and humidity, it will get very sweaty. Bring lots of water. The summit however can be a bit chilly if the wind is up, so bring a sweater.

Once you've reached the top you can follow the rim in a loop, and walk all the way to the crater to peer down to the now jungle-filled hole. On a clear day you can also see the other islands in the archipelago. Hot vents pouring out steam are also present on the top.

Hike down the same way you came up, and hail down a boat for a ride back in to town.