In my world the sea retreats thirty kilometres for seven years and then returns in one night, so what would a truly permanent coastal city look like?
My setting has two moons whose combined pull locks the coast into a fourteen-year “breath.” For seven years the sea slowly withdraws, exposing thirty kilometres of salt flats, old roads and stone foundations. On the seventh autumn it returns in roughly six hours. The date is predictable, but the final height is not.
Permanent settlements sit on black basalt anchor islands above the highest recorded waterline. During dry years, people build reed districts on the flats to harvest blue salt and repair routes that will later be submerged. Houses below are designed to come apart. Shrines remain fixed and are intentionally flooded.
The capital has occupied the same anchor island for nine centuries. It has courts, archives, observatories and schools, so I do not want it to feel like a generic camp that gets rebuildt every cycle.
What permanent institutions, property customs and neighbourhood identities would develop when half the city is only usable during alternating seven-year periods? How would you make this place feel continuous rather than two seperate cities sharing a name?