Located in the heart of the Landing beaches on the Gold Beach sector, the site of Arromanches-les-Bains is known worldwide for the presence of the remains of the Winston Churchill artificial port known under the code name Mulberry B. In June 1944, English engineers imagined forming stable jetties based on immense hollow and honeycombed parallelepipedic structures made of reinforced concrete. Able to float empty and be sunk at pre-determined locations, the 212 Phoenix caissons were designed to be towed across the English Channel at the speed of 5 mph (8 km/h). Then, once correctly positioned at their destination, they can be submerged in about twenty minutes thanks to valves placed at the bottom of the alveoli.