Question

What lakes are formed by the River Themes in the UK?

Answer 1

About 450,000 years ago, in the most extreme Ice Age of the Pleistocene, the Anglian, the furthest southern extent of the ice sheet was at Hornchurch in east London.[23] It dammed the river in Hertfordshire, resulting in the formation of large ice lakes, which eventually burst their banks and caused the river to be diverted onto its present course through what is now London. Progressively, the channel was pushed south to form the St Albans depression by the repeated advances of the ice sheet

Ice lakes :)