I'm guessing what ever you put there would get salt damage yearly and sand build also.
Pavers, concrete (maybe some stamped stuff), regular gravel would work. Any landscape rock (pea gravel, river rock, etc). Mulch would break down and be a yearly expense but works also (foot traffic could make this need a 2nd topdress mid summer).
Any trees on this? I have a HOA with a similar situation and pavers were the first choice but tree roots would of been in the way etc. I talked them out of pea gravel as kids would play in it and with mowers close by a window a year would be broke.
Looking for blown Kawi 29HP DFI engine's fd791d, whole thing, intake, throttle body, and electronic's. PM me if you have something you would like to sell.