Still struggling with the places part of this Quiz. They all contain a wet place. Any clues please to "swamp, in London" (6 letters) Have seen Slough suggested but that's not in London, and "grate + large body of water, in Essex" (8).
Slough
..."Slough (/ˈslaʊ/ (About this sound listen)) is a large town in Berkshire, England, on the western fringes of the Greater London Urban Area........
https://en.wikipedia.org/wiki/Slough