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
Canvey Island to Bowers Gifford and joins the London-Southend A13 at Sadler's Farm Roundabout. The two lanes of the A130 are currently the island's primary access route with 25,000 vehicles using the road and bridge per day. The B1014 and Canvey Road Bridge (or Canvey Bridge) crosses Benfleet Creek to South Benfleet, and provides access to the c2c London (Fenchurch Street) to Shoeburyness line via Benfleet railway station. Canvey Road Bridge was built in 1973, and replaced the island's first bridge to the mainland, which dated from 1931. The Colvin Bridge – named after the Lord Lieutenant of Essex, Brigadier-General R.B. Colvin