Mongolia: 100 monks in a cave

Mongolia caving, yay! Freezing temperatures and beautiful red granite rock of the Terelj national park near Ulaanbaatar, what's not to like? On my way to Mongolia I run into to other travelers from Finland, and they were able to join me on the Sunday excursion to Terelj. Together with a guide we headed to the 100 ламын агуй, or the 100 Monk Cave. Besides caves, we also looked at turtle-shaped massive rocks, world's largest horse rider statue, local population's ger (yurt) tents, and snowy mountains. The only question is if the cave will fit 100 monks as advertised ...

It was surprisingly difficult to find visitable caves in Mongolia. But since I was in Mongolia for the skiing, I also wanted to visit a cave... as this would be my 32nd country that I'd have been in caves at. I finally managed to find one, as our guide Nomuundalai Batdelger remembered a cave in the Terelj park. I had found many caves from Mongolia, but most of them were far away from Ulaanbaatar, and the short trip and the winter didn't really allow travel. For instance, travel to the Khoid Tsenkher cave would take some 17 hours by car to western Mongolia. By the way, I have a separate article about the caves in Mongolia for future reference if anyone wants to visit the caves that are publicly known.

The 100 Monk Cave is sitting next to the road through Terelj, so it is easy to access. We went first around the large rock to find where the cave entrance is, but the main cave entrance turned out to be on the front facing the road. You'll just have to climb up a bit. The entrance to the cave is a bit slippery, I think the rock has gotten smooth due to the many visitors, and of course the winter doesn't help the situation. I was afraid I'd fall if I was higher up the cave entrance, as it was sloping side ways up. Further inside the cave it was easy, as the slope was less steep and the surface was less slippery. There's two entrances to the cave, the lower and the upper, but at least I was unable to use the lower one, as the step down from that entrance was a bit sketchy. 

Then there's a side cave, which isn't really a proper cave as the rock just forms a small roof over the side of the big rock, so you can stay protected from the rain if you need to.

The main cave continues for 28.26 meters, so it is quite sizable for us Finns who have been used to tiny caves :-) Inside the cave, as is the tradition in Asia, people have brought small gifts: candles, cookies, a small toy horse, paper money, ... and even gold-colored goblets. While the entrance is just rock, further in the cave there's sand and dirt on the floor as well. The cave gets pretty low though in the end.

I loved the view out of the cave to the mountains on the opposing side of the valley. An example in the opening picture on this article.

So what about the 100 monks? Some doubts have been expressed if you really could have had 100 monks inside. Since I did a 3D scan of the cave, I got the length that was mentioned above, as well as the width that varies between 5 and 11 meters. If we take the average of those widths, we arrive at the floor space of about 225 m2. This is more than 2 m2 per monk, so assuming they are fine sleeping on a sloping rock, this should be plenty of space for the 100 monks to camp in :-) Definitely not just 10, as the sign next to the cave says. But also, 1000 would be too much.

About the 3D scans, I've been doing them with the iPhone's lidar, and using them to document caves. The scan was a bit troublesome this time though. My phone run out of battery in the middle of the process, maybe due to the -24 temperature in the morning. And then it run into some other issues, maybe software or just running out storage on the phone. I assumed the scans were lost, but it turned out that I was able to piece together a workable model from the two half-finished broken scans. That was a nice surprise! I used the 3D resulting model to draw maps (using the software I had written earlier), measure the length of the cave, and give an ability to look at the cave in 3D on your browser screen. More on this later in the article.

The cave is in these coordinates: N 47.8395200 E 107.3990359. There's a nice coffee and cashmere shop right by the rock outcrop, as well as a horse and camel riding on the other side of the road. The the side roof cave is at coordinates: N 47.839820 E 107.398632.

We also visited the Turtle Rock, a massive turtle-shape rock. Or a mountain, really. That too had a small cave-like space in a corner of the rock, in a crack between the different rock parts. To get to this crack, one has to climb up the right side of the rock until you find the crack. In the winter this was a bit challenging, as the snow and ice made again everything quite slippery. And the rock is very large. The coordinates for the Turtle Rock are: N 47.907703 E 107.422819.

Main cave pictures:

Here's the cave entrance from the outside, the cracking going horizontally up to the right:

Here is the 3D scan, turned into a horizontal map and some vertical cut-outs. Here's the plan view (horizontal) map:

And an example vertical cut view from point A. Note how the cave is slanted to the side.

The full map including all cut-outs is available in PDF format here. The 3D model can be downloaded in GLB format from here and Blender format here. You can rotate the model on your own browser screen by clicking on this link.

A screenshot of the model can be see below:

Fly-through in the model:

Views from the site:

Side cave pictures:

Turtle rock:

Lunch at a ger tent:

Tsingis Khan statue:

I also attempted to visit the (or rather "a") crystal cave nearby. More on that story in another article. And saunas and swimming in yet another article.

Read the full Planetskier series at planetskier.net, urban exploration stories from theurbanexplorer.net, and other underground stories from planetcaver.net, or all blog articles from Blogspot, TGR. Photos and text (c) 2025 by Jari Arkko, Grayden Prince and Hanna Mykkänen. All rights reserved.