Gunung Agung (Mount Agung) is the highest mountain on the small Indonesian island of Bali. Although peaks rise higher on Irian Jaya, Sumatra, Lombok, and Java, Bali's status as Indonesia's most popular tourist destination makes Agung perhaps the most-climbed high peak in the country.
Agung is a volcano with an enormous and very deep crater that occasionally vents out smoke and steam. The highest point is on the southwest part of the rim, a barren and rocky hill of fine volcanic rock. The summit area is above the treeline, due to the high winds and sterilizing effects of recent volcanic activity, but it is my understanding that the summit never sees any snow. Still, the weather of the surrounding rainforests of Bali is almost always cloudy, and the potentially awesome view of the entire island spread out beneath you is extrmely rare. Rinjani (12,224'/3726m) on the neighboring island of Lombok is often visble above the clouds, though.
The most commonly given altitude for Agung is 3142m/10,308', but this is an old elevation that does not take into account a volcanic eruption in 1963. When I was on Bali, I calibrated my altimeter to zero at sea level, and found the summit to be 2920 m. I reset it to 3142 m, but back at sea level it read -222 m. I had nver experienced my altimter to be that far off, so was stumped until someone saw my account on the web and told me that the real elevation is 3014 m, so my altimeter was only off by 94 m, still a bit, but not as bad as I thought.
The main trail to the summit begins in Besakih (approx. 1100 m), site of the island's largest and holiest temple complex, a sprawling, terraced sea of buildings. Guides are easy to hire if you look anything like a tourist--you will almost certainly be approached if you're a western backpacker type hanging out near the temple. It's best to start very early, as it's a long, long hike, of about 6,000 vertical feet or 2000 vertical meters. Bring a headlamp, since the sun never rises before 5:30 AM, and raingear, since you're in the equatorial rain forest.
You don't have to hire a guide, and the only reason I did on my October, 1993 climb was because I wasn't sure that the main trail I saw the previous evening was indeed the path to Agung. I didn't relish hiking uphill through the pitch-black rainforest in the rain with nagging doubts about where I was going, and my guide allayed those fears. The path was very straightforward and non-technical, although very steep in parts and washed out and brushy as it made its way through the jungle. It's not for the inexperienced hiker. Above timberline and a grafitti-scarred cliff, the upper parts of the mountain are a volcanic moonscape.