The better english: Locations
Pointing out a location is a common thing for people. Too often though do we also fail in giving out the correct location of things. I read something the other day and the message said a new location was adjacent to something when in fact it was on the opposite side of its reference landmark. So even if I thought that was easy to call, I felt responsible to give light to the confusion and finally an end to this misconception once and for all.
I say when in doubt, think right triangle. Yes from Geometry. Select any of those 3 angles and you have yourself a reference point. Now the two sides that meet at that similar reference angle are your adjacent sides. The side opposite that reference angle is well, the opposite side. As simple as that. With regard to locations, you can say opposite or across but NOT adjacent. You may argue that a person may still find the exact location anyway because the distance between adjacent and opposite places may not be well that far BUT it all comes down to precision. Opposite and adjacent is and will never be the same, there is definitely a difference and it pays to know how each should be used.