Fleet, River (England)

found: Work cat.: Ashton, John. The Fleet, its river, prison, and marriages, 1968:p. 2 (Only a tributary to the Thames, the River Fleet ... ) p. 25 (The Fleet ... owes its birth to an ornamental water, fed by springs ... in the park of Ken Wood, the seat of Earl Mansfield)

found: Wikipedia, Jul. 24, 2008(The River Fleet is the largest of London's subterranean rivers. It formerly flowed on the surface. It rises from two springs on Hampstead Heath and is directed into two reservoirs constructed in the 18th century, Highgate Ponds and Hampstead Ponds. From the ponds the water flows underground for 4 miles to join the River Thames.)