Borealis Planitia (Mercury)
"Northern plain"; from classical albedo name for quadrangle.
Borealis Planitia is a large basin on Mercury with a smooth floor, thought to be similar to a lunar mare. It is centered at 73.4° N, 79.5° W. The name is Latin for "Northern Plain". (wikipedia entry)
A planitia is a low plain. On Mercury they are named after names for Mercury (either the planet or the god) in various languages.
Image Source. Marker locations are approximate and may not always appear to align with image on map.
Borealis Planitia
74.7° N 279.91° E