Harley Street is where Margaret lives in the beginning of the novel. Due to the circumstances to Margaret's father surrounding his change in faith they are forced to move away from Harley Steet Margaret's mother expresses concern by stating, "how will Margaret bear our make-shift poverty after the thorough comfort and luxury in Harley Street,".
Margaret views Harley Street as a sanctuary in comparison to most other locations in this novel but after all the changes in her life this house seemed to block the pain from life. "found herself at once an inmate of a luxurious house, where the bare knowledge of the existence of every trouble or care seemed scarcely to have penetrated." The down side of this house is that has made her out of touch with the real world. This is house of safety and comfort.
Attached below is a link to pinstrest with pictures of Harley Street: https://www.pinterest.com/pin/230528074657192102/