Tham Pha Tai (ถ้ำผาไท) National Park in Thailand's northern province of Lampang (ลำปาง) covers an area of about 1,214 km² and is named after a cave located on a cliff, known in Thai as tham (ถ้ำ) and pha (ผา), respectively. The cave, which is caused by limestone mountains has a depth of about 1,150 meters, of which about 405 meters can be visited. It features some stalactites and stalactites along the way and on the right side of the cave wall, there is an inscription of King Rama VII's initials Po Po Ro (ป.ป.ร.) from when he visited Tham Pha Thai back in 1926 and referring to his name and title Prajadhipok Prom Rachatiraat (ประชาธิปก ปรมราชาธิราช), i.e. ‘HRH Prajadhipok’. The cave is home to a number of Horseshoe Bats, known in Thai as kahng kahw mongkut (ค้างคาวมงกุฎ), which literally translates as ‘diadem bat’, due to to the broad, horseshoe-shaped anterior nose-leaf, that characterizes these bats, a species with the scientific name Rhinolophus. Horseshoe Bats also possess large ears and a medium-length tail, which is fully enclosed in the interfemoral membrane, i.e. the membrane that stretches between the legs of bats and used for flight, as well as for catching insects. At the time of filming there was at least one Cave Dwelling Snake living in the Pha Tai Cave. It can easily climb the rocky walls and feeds on cave bats. This serpent, in Thai referred to as ngu kaab mahk hahng nin (งูกาบหมากหางนิล), has the binomial names Elaphe taeniura ridleyi and Orthriophistaeniura ridleyi, and is also commonly known as Cave Dwelling Rat Snake and Black-tailed Rat Snake. This species typically lives in or near limestone caves and preys primarily on bats. The top of its head is grey-blue with large, dark patches behind the eyes and an almost white throat. Its neck is orange-brown and gradates into beige toward the middle of its body, whilst a creamy-yellow vertebral stripe gradually appears, which usually gets darker and more visible as it progresses towards the tail. From the middle onward, the flanks become gradually black, whilst its underside also becomes creamy-yellow towards the tail-end. This attractive snake may grow up to 2.5 meters long. There are also some smaller cave dwelling creatures, such as Huntsman Spiders, giant free-roaming cave spiders of the genus Heteropoda, which among its genus has the world's largest spider by leg-span, i.e. the Giant Huntsman Spider (Heteropoda maxima), a cave dwelling spider that can grow to a leg-span of 30 centimeters.