To 22 ports; the busiest crossings are to Surrey Quays (4 minutes, 36 times a day), Canary Wharf (9 minutes, 36 times a day), Battersea Power Station (an hour, 36 times a day), Tower of London (20 minutes, 35 times a day), London Bridge (25 minutes, 35 times a day), Bankside (29 minutes, 35 times a day), Embankment (41 minutes, 35 times a day) and Westminster (45 minutes, 35 times a day).