-- Database schema
| station : Station_ID [ INT ] primary_key , Name [ TEXT ] , Annual_entry_exit [ INT ] , Annual_interchanges [ INT ] , Total_Passengers [ INT ] , Location [ TEXT ] , Main_Services [ TEXT ] , Number_of_Platforms [ INT ] | train : Train_ID [ INT ] primary_key , Name [ TEXT ] , Time [ TEXT ] , Service [ TEXT ] | train_station : Train_ID [ INT ] primary_key train_station.Train_ID = train.Train_ID , Station_ID [ INT ] train_station.Station_ID = station.Station_ID |
-- -- What are all locations of train stations?

SELECT DISTINCT LOCATION FROM station;