Rules say if there has been exploring, the discarded cards go back to their location pile, not the general discard pile
Does that mean they
a) get shuffled back into their location pile?
b) get placed back on top of their location pile?
c) does each location have a discard pile and you shuffle the discard pile when that location's draw deck runs out (like the street cards)
The Street cards go to the general discard pile and the Location cards return to its location pile.
It really doesn't matter if you shuffle them or not in this moment, because just before entering to a location you have to shuffle them.
So, in this case, both A) or B) are the correct answer, you can shuffle them or just place them on top of the pile. Just make sure to shuffle if you enter again on that location
Thanks to you!