text: Hi. Castlebrown is a townland also known as Clongowes. See details at https://www.townlands.ie/kildare/ikeathy-and-oughterany/mainham/balraheen/castlebrown/. Its border is defined in historic maps. E.g. go to http://maps.openstreetmap.ie/ and tick the overlay "MapWarper GSGS 3906 1:15K". It appears borders of the townland are accurate in openstreetmap. Perhaps locals use the alternative name Clongowes in the southern end of the townland. Both names are stored in Openstreetmap so I don't think any edits appropriate. Please comment and reopen if I misunderstand. Thank you.