Nahm tok Haew Narok (เหวนรก) in Khao Yai National Park (fig.) is a 3-tiered cascade, of which the name translates as ‘Abyss of Hell’ or ‘Hellish Abyss’, which is also nicknamed Susaan Chang Pah (สุสานช้างป่า), i.e. ‘Wild Elephant's Graveyard’. A nature trail and a steep staircase lead to a viewpoint at the base of the waterfall, which is the largest waterfall in the National Park.

Along the trail are some small stone statues of elephants, that have all but corroded away by the natural elements. The statues serve as a of memorial to elephants that have died falling into the waterfall. According to statistics these kind of accidents tend to happen regularly, with 1 to 2 deaths annually nationwide, while in August 1992, a herd of eight wild elephants died when they fell into the abyss of Haew Narok.

Sadly, on 25 October 2019, again six wild elephants died here after falling into the waterfall, 5 of them whilst trying to help a circa 3 year old elephant calf that had fallen into the first tier of the waterfall.

The six elephants were swept away and drowned, and their bodies ended up at the base of the waterfall, that on this day once again lived up to its name, while two more struggling animals, one believed to be the mother of the calf that drowned, were rescued by park officials.

However, a few days later and nearby five more dead elephants were spotted by drone footage, thus bringing the total deaths to eleven pachyderms, all believed to belong to the same herd, and making it one of the biggest losses of wild elephants living in National Parks in Thailand on record.