[americanophile]

In other words, sea level rise has been going on for thousands of years and is not a new postindustrial phenomenon.

[Citizen Tom Paine]

The sea level has risen about 300 feet since the last ice age ended. The really ancient civilizations are on the continental shelves which ring the continents. Look there my friend and you will be amazed. I would look at the old river mouths for starters.