KHON ISLAND, Laos — A German backpacker with braided, red-tinted hair and a Lao tourist, perched on a tree branch like a giant parrot, gaze intensely from a rocky islet onto the vast, shimmering expanse of the Mekong River.
They're hoping to glimpse the perpetual smile of an enchanting creature legends say was once a beautiful and tragic woman.
It's hardly a drop-in tourist destination. This stretch of the mighty, 2,700-mile Mekong is set in the remote, southwestern corner of Laos. Not long ago, murderous Khmer Rouge guerrillas roamed the malarial jungles on the opposite bank in Cambodia.
But now more adventurous visitors are coming to what the Lao call Siphandon, or 4,000 Islands, a marvelous waterworld of rushing falls, traditional riverine hamlets, French colonial relics and the loved but endangered Irrawaddy dolphin.
Siphandon encompasses a 31-mile section of what appears more like a lake than a river because here the Mekong balloons out to as much as 8.7 miles , the widest point along its entire course.
The islands range in size from Khong, with some 55,000 residents, to uninhabited isles draped with lush vegetation, to tiny outcrops sustaining a tree or two, their branches bent by currents of the monsoon-swollen waters which yearly drown much of the vegetation.
The riverscape's languid mood is dramatically shattered at the Khone Falls, cataracts over which the river roars and foams like a furious charge of silver-maned stallions.
The volume of surging water — 2.5 million gallons per second — is the greatest of any waterfall in the world, nearly twice that of the Niagara Falls.
This barrier is a key reason why the Mekong remains one of the last great rivers on Earth to have avoided major development.
One of the key islands in the Mekong — Khon, dubbed the "Tahiti of Laos" — is still an idyll of Southeast Asian rural life. Children play in coconut groves, fishermen ply the waters in little skiffs, women in sarongs gather at sunset to bathe in the river.
"Tourism is certainly having a dramatic influence on people in tourist areas — some good things, some bad," says Ian Baird, a Canadian environmental expert. "The capacity of the area to absorb tourists is certainly an important concern for the future."
On the positive side, Baird says, tourism may be the one savior of the Irrawaddy dolphins, which probably number less than 100 from the thousands that once inhabited the Mekong.