This temple's name is Wat Khao Daeng. Wat means temple, Khao is mountain and Daeng is Thai for the color red. So, in English, you would say Red Mountain Temple. Now, at the summit of Khao Dang (Red Mountain), where we hiked in the early morning, if we had ventured onto a side trail, or re-positioned ourselves up on the rocks, we might have seen this temple down below. I wasn't very prepared on this front, so we didn't even really look for it. If you want to see Wat Khao Daeng from that perspective, click here.
On the way by car to the trailhead where we started our hike up Khao Daeng, we actually passed Wat Khao Daeng (a bit off in the distance), and I remembered it from my online pre-trip research. After our hike we asked our driver to take us by the temple. We got out and took these and some short videos. I have yet to do anything with the short video clips, but if I do something, I will add it here. My advice to travelers is to not assume your tour through your resort is going to include this temple with the hike up the mountain. Therefore, if you want to see it, inform your driver on the way to the hike, or after. You will see it. All you need is 15 minutes. They even had a station for iced drinks, and I think I even saw monkeys on the temple grounds! Once you get back to your resort or hotel, tip your driver a bit more for this side-journey.