The four pieces of granite pilars are the foundation of two flag poles. They used to have two very big poles being tide between the rock, but now they are gone from decay and only two big bamboo sticks remained.
That particular piece of ceremic decoration reads 宣統弍年. If converted back to AD that would be 1910. That means the decorations was placed there in the second year of the last Emporer of the Qing Dynastry. The Qing was done in 1911........
Those are Sek Wan cemeric handicraft (石灣陶瓷) and they had been treasured craftmanship back then. It was most unfortunate that many grand masters didn't make it through the so called cultural revolution. If you happen to come upon one of those dated back in Qing dynaster or before in the market, it could cost you an arm and a leg.