Rock bang full of oysters
You've just got to love Portland Stone, with its distinct facies. This is grove whitbed, a Jurassic limestone famous for being absolutely full of oysters. I took this one, I think, at Green Park tube station in London. The station entrance, on Piccadilly, is literally a work of art; called Sea Strata, it was created by John Maine RA with the building clad in different facies of Portland Stone. This is the highly fossiliferous Grove Whitbed, which is full of oyster shells.