The Mountains of the Moon is the name of a mysterious misty-covered, tall mountain range somewhere in Africa, and the location of the wizarding school Uagadou (Pm). The Mountains of the Moon were written of in antiquity as being the source of the Nile River. Today, Muggle geographers are unsure which mountains were being described by these ancient writers. One of the more probable locations is the Rwenzori Mountain Range in Uganda and the Democratic Republic of the Congo.
The fact that Muggle geographers can't figure out exactly where the Mountains of the Moon are suggests that there are powerful enchantments in place to protect the school, probably including Muggle Repelling Charms.