The two-day trek costs about $65 per person for a group of at least 3 people — more for couples or single travelers. This is a fair price, and much of the money goes to local villagers who guide groups through the mountains and cook delicious meals.
Travelers start out in Tha Khaek, a medium-sized town on the Mekong River that’s about halfway between Vientiane and Pakse.
I would recommend booking the trek in advance at the tourist information centre in Tha Khaek. Guesthouses like the Travel lodge in Tha Khaek can also book it for you.
Remember that the wet season is from July through October. It is best to take on this trek between November and March when the temperatures are pleasant and the weather is dry. April and May bring the hot season, during which the many swimming holes along the way will make the trek very enjoyable.
The trek explores the Phu Hin Bun National Protected Area (NPA), an isolated region of jagged peaks and clear, turquoise streams that looks like a classical Chinese landscape painting. The sheer mountainsides are refuges for several species of endangered primates, and tigers stalk the deepest parts of the jungle.
The villagers who live in the Phu Hin Bun NPA are largely self-sufficient, growing rice, fruit and vegetables, and raising water buffalo, pigs, chickens, and cows. While many treks in Laos visit ethnic minorities, the villagers here are mostly lowland Lao.
I LOVED the food on this trek. Fresh catfish grilled with garlic over a campfire on the banks of a stream was served alongside sticky rice, mountain vegetables, eggplant, and traditional pastes of herbs and chili.
For dinner we ate water buffalo laap, a Lao dish of minced meat with herbs and spices. Vegetarian options were limited, but available.
The walks through the forest were broken up by frequent stops at spectacular swimming holes, including a sacred wellspring of turquoise water called Khoun Kong Leng.
Other highlights included a cave that links two valleys by cutting straight through a mountain, and an old temple where the prayer bell was made from the shell of a 500-pound bomb. This bombshell was a poignant reminder of the massive U.S. bombing campaign of rural Laos — a war that the White House kept secret from both Congress and the American people.
Visiting this part of Central Laos is a privilege, and travelers should take care to respect Lao customs. Understand that Lao people are extremely non-confrontational and place a premium on smooth social interactions.
Be gentle, kind, patient, and appreciative. Showing any sign of frustration or anger is extremely rude in Laos, so if you don’t like something it’s better just to smile and, if you must, gently inquire about alternatives. The head guide will speak reasonable English, but speak slowly and try to learn some Lao words. Everyone will be thrilled to hear you make the effort. 
This article was originally published on April 11th, 2009