Located in the east of Loei province , just before the border with Nong Bua Lamphu province, Wat Tham Erawan is not very well known. Yet its Erawan Cave perched in the mountain above the temple is very photogenic with its large seated Buddha at its entrance. The cave itself has a main chamber divided into smaller rooms each with stalactites and stalagmites and a few more Buddhas images but if you don't have a powerful flashlight you won't be able to venture very deep as there is no lighting (well, there is but it does not work). The flashlight function of your smartphone will be insufficient (I tried). So be prepared because there is apparently an opening with a beautiful view at the back of the cave.
The cave is accessed from inside the temple grounds via a staircase. The ascent is actually quite quick and not that steep. It took me less than 15 minutes to go up to the mouth of Tham Erawan and its seated Buddha. On the way up or down you will have some pretty views over the valley through the trees. The rest of the temple is less interesting but I noticed a pretty golden sitting Buddha under a tree.