The kanji compound 場所 is bugging me. For the longest time, I did not know how to pronounce it, oscillating between ばどころ and じょうしょ. The correct pronunciation, however, is ばしょ. This is weird to me, because it is a kun-on compound rather than the more typical on-on or kun-kun. In my experience, the most usual case when characters are read ‘weirdly’ is those readings being ateji. However, in most cases ateji are uniquely Japanese but in the case of 場所, a Chinese compound of the same meaning exists which usually points to an on-on reading (compare e.g. 交通, a wholly random example that I managed to think of immediately, that has a direct Chinese corresponding word).
So how did the word 場所 originate and how did it acquire its pronunciation?