Pura Luhur Lempuyangis one of the 9 'directional' temples in Bali, and on this basis it has a particular importance for the island's inhabitants. They are actually a group of temples that you can access following a road and, if you wish to go to the highest temple, by climbing the 1700 steps that lead there... Let me tell you that it's best to be motivated, especially as the highest temple is often closed and/or covered in mist.
Despite that, the walk is really pleasant and the view over the surroundings is worth seeing when the sky is clear. Also be aware that the temperature at the last temple is not the same as that at the first, so according to the season warm clothing does not go amiss. Discovering Bali by visiting Pura Lempuyang is dipping your toe into the very particular culture of this island.
Of all the temples I saw in Bali, Pura Lempuyang is the one that most impressed me. It's completely different from the other temples you can visit when you visit Bali. Unlike Tanah Lot and Uluwatu, Pura Lempuyang receives few tourists, and it's one of the rare temples in Bali where you get a real sense of the religious aspect of the place.
I particularly appreciated the fact that for once there was nobody putting the hard sell on us to get us to buy a sarong or pay for a guide. You are completely free to look around this temple on your own. The first of the buildings is the most spectacular, and its "door" opens out onto a view of the magnificent Mount Agung. After that you go on a long walk from one temple to the next before finally arriving at the highest point: Pura Lempuyang itself.
I find it a bit regrettable that the Indonesians don't take more care of their temples. There are piles of rubbish scattered on the ground here, which is something I find saddening to see when I visit a religious site.