This 2538-sq-km sanctuary has the country's highest peak, Phnom Aural (1813m), and is just east of the Central Cardamoms National Park. Unfortunately the area is being destroyed from the south and the east by corrupt land speculation and rampant illegal logging, but the long-standing and reputable DutchCo Trekking Cambodia runs three-day trips to the region. Phnom Aural can be done in a day, but most do it in two or three.