Telford designed the bridge. They started building it in 1819. The first thing to be built were the towers that are on both sides at Holyhead and Anglesey. The towers were made out of limestone from Penmon. They were hollow inside. After the towers were built, 16 chains were installed. They were made out of 935 bars of iron. They were long enough to support the long bridge. Iron can rust. So, the people who made the chains soaked them in linseed oil and the painted. The chains were long and weighed 121 tons. The bridge opened on January 30, 1826.