The Garden of Endless Pillars is one of the domains you can find in Sumeru, the latest region added to Teyvat in the Genshin Impact 3.0 update (opens in new tab). It's partially buried in sand so even if you find it when you're out exploring the new Dendro region, you might have trouble figuring out a way to get into it.
You can only run this dungeon once but the rewards include Primogems, Dendro Sigils, ascension materials, and Mora so it's worth unlocking it to nab those goodies. If you're ready to get started, here's how to unlock the Genshin Impact Garden of Endless Pillars domain.
Genshin Impact Garden of Endless Pillars location
The Garden of Endless Pillars domain is found in the northwest area of Sumeru. It's almost directly north of the large mausoleum and you'll find there's no real way inside as the entire thing is buried with just the top sticking out of the sand. If you have a look around the immediate area though, you'll find several Pyro monuments and you'll need to activate these in a specific order to access the domain.
How to unlock the Garden of Endless Pillars domain
To activate the Pyro monuments, you'll need a character that uses the same element. The easiest option is Amber and her charged bow attack works perfectly. The order in which you need to activate the monuments isn't quite so easy to figure out, however.
First of all, look at the Flaming Flowers found around the area. You should notice that they are growing fairly close to the Pyro monuments and these will help you work out the correct order. Basically, the first monument you need to activate should have no flowers near it, the second should have one flower nearby, the third have two, and so on. The video (opens in new tab) above shows you the correct order if you're having trouble.
Once you've successfully activated all five Pyro monuments, the domain will rise out of the sand and you can access it whenever you want. Good job.