Tell the host city of the 1968 Winter Olympic Games.
host city refers to city_name; the 1968 Winter Olympic Games refer to games_name = '1968 Winter';
SELECT T2.city_name FROM games_city AS T1 INNER JOIN city AS T2 ON T1.city_id = T2.id INNER JOIN games AS T3 ON T1.games_id = T3.id WHERE T3.games_name = '1968 Winter'