Before the Fleet River was covered in 1737, Holborn Bridge spanned the junction of the Fleet and Holborn rivers. In Roman times, the Fleet was a major river, but over time, as London grew, it became used more frequently as a sewer, what with several prisons and poor housing nearby. The bridge stood on the site of the Victorian Holborn Viaduct.
In his Horatian satire of London, "A Description of a City Shower" (1710), Jonathan Swift references the Holborn Bridge in an accurate description of London's early 1700s drainage system. In Swift's time, the sewage would have drained into Fleet Ditch/River at the Bridge.
Now from all parts the swelling kennels flow,
And bear their trophies with them as they go:
Filth of all hues and odors seem to tell
What street they sailed from, by their sight and smell.
They, as each torrent drives with rapid force,
From Smithfield or St. Pulchre’s shape their course,
And in huge confluence joined at Snow Hill ridge,
Fall from the conduit prone to Holborn Bridge.
Sweepings from butchers’ stalls, dung, guts, and blood,
Drowned puppies, stinking sprats, all drenched in mud,
Dead cats, and turnip tops, come tumbling down the flood. (lines 53-63)