Timothy Pont mapped the area in the 1590s, and his work appeared in the maps of the Dutch cartographers Hondius (1630s) and Joan Blaeu (1654). Interestingly, Blaeu gives the name in two forms, in two different locations: Pentland Hill (roughly in the area of Castlelaw); and Penth-landt hill (further south and clearly intended as a name for the wider range).