 It was also chosen in 2018 for the location shooting of the German television series "Das Boot" (a sequel to the 1981 Classic).The bedrock of La Rochelle and surrounding areas is composed of layers of limestone dating back to the Sequanian stage (upper Oxfordian stage) of the Jurassic period (circa 160 million years ago), when a large part of France was submerged.Many of these layers are visible in the white cliffs that border the sea, which contain many small marine fossils.