It has been there since before the last Ice Age - around 10,000 years ago, so nobody knows for sure.
The river Thames is the largest river in the UK.
At the Thames Head in Gloucestershire, UK.
The main river in the UK is the River Thames. It is the longest river entirely within England, and it flows through the capital and most populated city in the UK, London.
River Severn River Thames River Trent
thames
The River Thames is the best known river.
The Capital of the UK is London, which is on the Thames River.
The river Severn. It beats the Thames by about 3 miles.
The largest city on the banks of the Thames River is London, the capital of the UK.
Thames
Old Father Thames.
The River Severn, River Trent and River Thames.