Shanghai has a beach! And it's way out in Jinshan on "line 22" which actually isn't a line at all, it's a bullet train. You can use your metro card though, and you don't need your passport. Tickets down there cost 10rmb, then entry to the beach area itself during peak season is 30rmb weekdays, 50rmb weekends and holidays. Off season is 10rmb weekdays and 20rmb weekends/holidays.