From Discworld & Terry Pratchett Wiki
Welcome Soap is a street that runs parallel to the river Ankh (only one block away) continuing from Cable Street. At Cheapside it splits into Filigree Street going straight hubwards, and Heroes Street in hubwards/widdershins direction.
The street houses mainly small traders, porters, butchers and longshoremen. The only significant character in the series who lives here is Miss Drapes, the bank clerk in Making Money. It is also the home location of Mrs Harms-Beetle, an otherwise unseen, unspeaking and undescribed friend of Mrs Evadne Cake, whose only role in Making Money is to facilitate an inhumation attempt.