How many mountains are there on the African Continent?
SELECT COUNT(T3.Name) FROM country AS T1 INNER JOIN encompasses AS T2 ON T1.Code = T2.Country INNER JOIN continent AS T3 ON T3.Name = T2.Continent INNER JOIN province AS T4 ON T4.Country = T1.Code INNER JOIN geo_mountain AS T5 ON T5.Province = T4.Name WHERE T3.Name = 'European'