 This form was defined two decades before the Mongolian name got its current Cyrillic script spelling and "Ulaanbaatar" transliteration (1941–1950); however, the name of the city was spelled "Ulaanbaatar koto" during the decade in which Mongolia used the Latin alphabet.Today, English speakers sometimes refer to the city as UB.Human habitation at the site of Ulaanbaatar dates from the Lower Paleolithic, with a number of sites on Bogd Khan, Buyant-Ukhaa and Songinokhairkhan mountains, revealing tools which date from 300,000 years ago to 40,000–12,000 years ago.