Hopewell Rocks

Hopewell Rocks stands on the Bay of Fundy shore in New Brunswick, Canada, where the tidal range is the largest measured anywhere on earth — up to around sixteen metres. The site is a set of sandstone sea stacks, undercut by the tide into shapes usually described as flowerpots, standing on a beach that exists twice a day.

It exists because of that range. The bay's shape and length put it in resonance with the Atlantic tide, amplifying it enormously; the volume of water moving in and out of Fundy each cycle is greater than the combined flow of every river on earth. The tide has cut the base of these stacks while their tops, above the waterline, still carry trees.

At low water you walk on the sea floor between the stacks, on wet gravel and mud, with the undercut rock overhead. Roughly six hours later the same ground is under ten metres or more of water and kayakers paddle among the tops of the same formations. The transition is not gradual in feel — the water moves fast and the site closes the beach well before high tide. The stacks have names — Lover's Arch, E.T. Rock, the Bear — and they change: Elephant Rock lost its head to a collapse in 2016, which is a reminder that the undercutting that made them is still going on.

It is run as a provincial park: interpretive centre, stairs down to the beach, a shuttle, and staff who close the access on schedule. Entry is charged and the site has published tide times that determine what any given visit will be.

Everything here depends on the tide table and nothing else. See both states in a day and the visit makes sense; arrive at the wrong hour and it is a locked gate or a car park. The Bay of Fundy moves a hundred billion tonnes of water twice a day and this is where you can stand in the middle of it and then, six hours later, kayak over your own footprints.