Here's drone footage of the remnants of the structure.
It's far too complex for a minimal beach access. Although construction columns look like slipform reinforced concrete, the extra steel tube seems unnecessary.
The confounding factor is how it's buried into the sand with a golf course on top of it. If that was a recent structure, then that sand accumulation wouldn't have been stable for people right on the edge. It's likely old & buried, suggesting an unknown history.