Mount Agung is at the left; Mount Batur, or what remains of it, is to the right of center. - NASA

Indonesia is the world’s longest archipelago. It’s thousands of islands offer uncountable and diverse attractions, both natural and cultural. Not the least of these is a plethora of impressive and accessible volcanoes.

Most Indonesian islands are, like Hawaii, just volcanoes rising up from the ocean floor. Perhaps the most famous of these is the storied tropical paradise of Bali. Bali’s Gunung (Mount) Batur offers a wealth of possibilities.

Batur was once a massive and tall, volcano, but it long ago blew its top off at the 5,500 foot level. The huge crater which remains within contains several villages, a large lake which covers the eastern third of the old caldera, and an impressive "new" central and active volcanic cone. The view from the outer rim, especially from the south at Penelokan, is simply spectacular. The central cone’s last major eruption sent lava flowing down and swallowing the village of Batur in 1926. You can still quite clearly see the path of the flow and can wander through the ruins of the village. Other villages which remain along Lake Batur’s western shore offer a variety of guest houses for over-nights.

Climbing to the top of Batur’s new cone from the crater’s floor is a tough but rewarding challenge. Guides are available, but not necessary; just keep going up. Many start off about 3:00 AM in order to be at the rim for the 6:00 AM sunrise, but a later start is OK, as long as you summit before the frequent afternoon clouds roll in. In the dark, you can see flames leaping from deep within the central crater.

There is a semblance of a trail which circles the rim. On the west side, the rim is very steep and thin. Here you may find yourself facing in with your fingers curled tightly over the edge and peering almost straight down into the crater as you crabwalk along sideways. You will be only slightly embarrassed by the young girl vendor, wearing flip flops and carrying a heavy cooler-bucket full of iced soda pops, who races confidently along the edge, careful to avoid stepping on your hands.

You will pass steam and sulfur vents where young locals may offer to boil or fry you an egg. You may also see some very large, but thankfully shy, wild monkeys.

Another adventure awaits below. On the far, eastern edge of Lake Batur, isolated snug up against the vertical crater wall, lies the Bali Aga village of Trunyan. The Bali Aga are the ancient aboriginal inhabitants of Bali. They were overrun about 700 years ago by Hindu worshippers who now dominate the island, There only a few Bali Aga villages left. Trunyan is accessible only walking around the lake or by boat. It is possible to hire a motorboat to Trunyan at the village of Kedisan or to rent a dugout canoe near the hot springs at Toyah Bungka and paddle across. But be forewarned, it is further than it looks. Trunyan’s main attraction is the “cemetery”.

The Bali Aga do not bury their dead. Instead, they lay the corpses out under bamboo frames to decompose naturally. The bodies are put beneath a huge tree which is believed to absorb any unpleasant odors. (As far as I could tell, the tree works.) After some time, when all the flesh has fallen away, villagers will take the bones and rearrange them with those of earlier deceased: all the femurs here, ulna there, a line of skulls on the wall. It makes for a unique, albeit eerie experience for sheltered Westerners.

A drive to Gilimanuk at the west tip of Bali, the short ferry ride to Banyuwangi, East Java, and 4 or 5 hour drive west to Probollingo takes about one day. Probolinggo is the gateway to Gunung Bromo at the center of the Tengger Massif and the Bromo-Tengger Semeru National Park. Bromo is a 7,650 foot active volcano, one of several which dot the spectacularly desolate 6 mile-wide Tangger crater floor.

From Probolinggo, drive up the progressively more alpine and beautifully green, fertile slopes of Tengger to “overnight” in the village of Ngadisari or Cemoro Lawang. Again, the aim is to rise early, 4:30 or so, to beat the sunrise at Bromo. From the Tengger rim, you descend steeply by trail to the crater floor and begin hiking across the sandy crater floor, about one hour to the foot of Bromo. (It is possible to rent a horse here.) There is a 250 step stairway up Mt. Bromo. At the summit, before sunrise, fire is visible roaring from the main vent within. You can again, given the energy, circle the crater on a good trail. The views of neighboring volcanoes, especially the unique and uniformly fluted slopes of Mt. Batok, are awesome.

Indonesian tourism has taken a severe and undeserved hit since the well-publicized terrorist bombings of a few years ago. Avoiding Indonesia now makes about as much sense as avoiding New York since 9/11. Indonesia may be the largest Muslim nation on earth, but the version of Islam found here is both casual and broadly tolerant. The people are uniformly warm and solicitous. And Bali, of course, is not Muslim at all, but Hindu. The Balinese are famously spiritual, reverent, sweet and gentle.

Given the current bargain prices and embarrassingly appreciative welcome you will get, this is the best possible time to visit Indonesia.