Isle of Sheppey Yantlet Creek at the Isle of Grain to the west, it was occasionally used in ancient times by shipping to and from ports such as Chatham and London to reduce exposure to bad weather in the Thames Estuary or North Sea. The Kingsferry Bridge was first built in 1860, thus eliminating the need for ferries. Over time, there have been four bridges built over the Swale at this point. All bridges had to allow sufficient clearance for shipping heading to the commercial docks at Ridham: On 5 September 2013, fog caused a 130 vehicle pile-up on the Sheppey Crossing bridge
Yalu River its length. Most of the river freezes during winter and can be crossed on foot. The depth of the Yalu River varies from some of the more shallow parts on the eastern side in Hyesan (1 m) to the deeper parts of the river near the Yellow Sea (2.5 m). The estuary is the site of the Amrok River estuary Important Bird Area, identified as such by BirdLife International. About 205 islands are on the Yalu. A 1962 border treaty between North Korea and China split the islands according to which ethnic group was living on each island. North Korea