Tidal waters reach Teddington, 62 miles / 100 km from its mouth, where the first lock from the sea (except for the tidal lock at Richmond) is located.
There are in all 47 locks, St John's Lock, Lechlade, being nearest the source. They face the South Downs across the Weald of Kent and Sussex and are much used for sheep pasture.
One of the Fat Badgers has travelled the whole of the British Mainland Coastline - But that was in a car.
In the west of the range Butser Hill, the highest point, rises to 271 m / 887 ft and Duncton Down to 255 m / 836 ft; in the east Ditchling Beacon rises to 248 m / 813 ft.
Line of chalk hills in Southeast England, running from near Petersfield, Hampshire, across Sussex to the south coast at Beachy Head near Eastbourne.
They face the North Downs across the Weald and are used as sheep pasture.
It was built about AD 785 by King Offa of Mercia, England, and represents the boundary secured by his wars with Wales.
The dyke covered a distance of 240 km / 149 miles, of which 130 km / 81 miles are still standing.