As you reach the end of the central Thai floodplains, you will be meeting the Tennasserim hills.
The hills ahead of you are actually the foothills of the Himalayas. They link through Laos, Burma, and China, all the way to the top of the world – Mt. Everest.
At this part of the journey, the River Kwai bulges into a lake at the beginning of the Tennaserim hills, which divide the flood plains of Thailand from Burma and the Indian Ocean with a range of granite and limestone. Generally, the subtropical rainforest on the Western side will be thicker and more lush from the weather coming from the Indian Ocean, and it will get thicker the further into them you head.
In 2011, a Bell Iroquois helicopter went out looking for illegal loggers from Burma and crashed in these mountains not too far to the south from here. Two days later, a Royal Thai Army Black Hawk that had been sent out to recover five bodies of victims and also crashed. A week later, a third Bell 212 military helicopter also succumbed in this same area. The more scientific blamed the first two crashes on bad weather, and the third on a rotor failure. But the more superstitious Thais blamed the consecutive crashes on the mountain range’s strong and two-faced guardian spirits: on a good day, they are benevolent protector of the riches of the earth and trees, but on bad days they can be trecherous ghosts known to divert and even devour unsuspecting travellers.
Overlooking the lake on the hill behind it are two temples – Wat Tham Faet is on the Bangkok side of the hill, and Wat Tham Mangkornthong on the Nam Tok end. Perched overlooking the lake, these Wats are remarkable because they are the entrances to caves that burrow deep into the limestone hill. These caves are considered holy places deserving an assortment of shrines and gold-covered statues. On a hot day, they can be a cool retreat from Kanchanaburi, and can be reached by a quick taxi ride. In between the caves, you will see an unfortunate scar – a limestone quarry for Thailand’s cement industry.