Farthest north: Jostedal, Norway (61n33, 6e?) or that general area
Farthest south: Santiago, Chile (33s27, 70w40)
Farthest east: Stockholm, Sweden (59n20, 18e03)
Farthest west: Corvallis, Oregon (44n34, 123w16) (etb can tell me if I have in fact been farther west)
These four points can be used to define a rectangle (well, in more-or-less spherical geometry they do) whose borders lie along the lines of latitude and longitude you have identified.
What’s at the center of this region? 14n3, 52w37: the Atlantic Ocean, north of Guyana and east of Grenada.
Have you been there? No.
Where is the nearest place to the center you have visited? Somewhere in Florida. Maybe Sanibel Island, or maybe Miami, if I've been to that airport.