[oldandtired]

If you want pristine sand beaches then expect major change over time. Looking at areas where there is little change over time, certain coastal structures are in plain sight.

But as many have already noted, the sea erodes all coastlines. However, what the sea takes away at one time, it also brings back in another time. When my father was in his teens, the water's edge for a small residential site was over a mile away. By the time I was in my teens, that distance had been reduced to 30 metres. By the time I was in my late twenties and early thirties, the water's edge was now at half a kilometre further out. Since then (I'm in the mid 60's) that beach has has grown and receded a couple more times.

Moral of the story, build only where there is relatively constant conditions.