Question: What  attraction type do most tourist attractions belong to? | Did  you want  to  know the attraction type that most tourist attractions belong to? code  or  description? | Yes, can you give me the codes please?
SQL: SELECT  T2.Attraction_Type_Code FROM Ref_Attraction_Types AS T1 JOIN Tourist_Attractions AS T2 ON T1.Attraction_Type_Code   =   T2.Attraction_Type_Code GROUP BY T2.Attraction_Type_Code ORDER BY COUNT ( * )  DESC LIMIT 1