River Thames shipping coming in and out of London, in 1732 it received the world's first lightship. This became a major landmark, and was used as an assembly point for shipping. Today it is marked by Sea Reach No. 1 Buoy. The River Thames contains over 80 islands ranging from the large estuarial marshlands of the Isle of Sheppey and Canvey Island to small tree-covered islets like Rose Isle in Oxfordshire and Headpile Eyot in Berkshire. They are found all the way from the Isle of Sheppey in Kent to Fiddler's Island in Oxfordshire. Some of the largest inland islands, for example
Inner Tay Estuary Inner Tay Estuary The Inner Tay Estuary, the inner, western part of the Firth of Tay, stretching from the Tay Railway Bridge in the east to the Queen's Bridge over the River Tay in Perth and the bridge in Bridge of Earn on the River Earn. The estuary is one of the largest in eastern Scotland and is up to 2.5 km wide. The estuary consists primarily of inter-tidal sand and mud flats that extend seaward out to the main channel of the estuary, the majority of which lie on the northern shore. Landward of these are saltmarsh and "Phragmite"s