<a href="https://en.wikipedia.org/wiki/Ordnance_Survey" class="extiw" title="w:Ordnance Survey">Ordnance Survey</a> map showing <a href="https://en.wikipedia.org/wiki/Brompton_Road_tube_station" class="extiw" title="w:Brompton Road tube station">Brompton Road</a> station on the <a href="https://en.wikipedia.org/wiki/Great_Northern,_Piccadilly_and_Brompton_Railway" class="extiw" title="w:Great Northern, Piccadilly and Brompton Railway">Great Northern, Piccadilly and Brompton Railway</a>. Original map scale: 25 inches to One Mile/880 feet to One Inch.
<a href="https://en.wikipedia.org/wiki/Ordnance_Survey" class="extiw" title="w:Ordnance Survey">Ordnance Survey</a>
<a href="https://en.wikipedia.org/wiki/Ordnance_Survey" class="extiw" title="w:Ordnance Survey">Ordnance Survey</a>. London (1915 Numbered Sheets IV.16). Public Domain as published more than 50 years ago.