Twice a day the tide rolls up Turnagain Arm — the long, shallow inlet south of Anchorage — as a single wave, sometimes six feet high, travelling at fifteen miles an hour. It is one of the largest bore tides in the world. In summer surfers and stand-up paddleboarders catch it; on a still day you can hear it coming.
The Seward Highway runs along the north shore and gives several pullouts with good views: Beluga Point and Bird Point are the standard spots. Check the tide tables — the bore typically arrives an hour or two after low tide at Anchorage, depending on the moon phase.