The center of the city is a very safe place but if you visit the not very modernized places around ulaanbaatar i think it will be a little bit dangerous. Those areas have lot of drunk people and also childrens that are alone and beg money(But not all of them). And the countryside is the safest and most peaceful place in the entire universe.

Every city has 2 side. Please always keep you safe. No matter safe city are u in never go to rural area alone after dark. Ulaanbaatar is quite chill and safe but as i mentioned there is good and bad. Suburs can be getho. Whatever you go , be smart. Dont go alone after dark, dont go to suburs alone as well.

It is generally safe as long as you know what you're doing and where you are going. However, some people can be quite physical, especially in public transport. Most Mongolian people tend to be physical in such settings, but don’t worry—they're not as mean as they might seem.