I went in early May 2024. It was closed until Thursday, I had to stay late. Admission is 20,000 tugriks, a child of 8 years old is free. It works from 9 am. There is a Burger king and a KFC near the museum. Stuffed animals. Fish, butterflies, birds. I advise you to visit!
The museum is very informative, tells in an accessible form about the development of the Earth and life on it from the earliest to the present day. Sometimes volunteers from local high school students are on duty, they speak English and some in Russian.