I don't think #361 is correct. One reason is that blacks last move could have been Kg7-h7 moving out of the check.
Hardest mate in 1 puzzles

fxg6#
The pawn on a3 started in the e file because the pawn on b5 started on the a file so it actually came from b4 and thus it wasn't blacks last move. For the other pieces there is nothing tricky, the last move black made was g5.


Is it mate in 1?

this is the first smart mate in 1 puzzle ive ever seen
White to move and find a move that is NOT checkmate. Good luck!
Rc6, since it unpins the black rook allowing it to take the bishop on h7

White to move and find a move that is NOT checkmate. Good luck!
I saw that puzzle in a museum

White to move and find a move that is NOT checkmate. Good luck!
Rc6, since it unpins the black rook allowing it to take the bishop on h7
Correct

LOL this is the link where you got this position: https://thechessworld.com/articles/problems/3-most-tricky-mate-in-1-positions-ever/

LOL this is the link where you got this position: https://thechessworld.com/articles/problems/3-most-tricky-mate-in-1-positions-ever/
haha, yeah
But why? Black cannot castle, he is in check. Also, c6 is the only check for white.
EvinSung got it right but he only gave part of the answer. You can prove it's blacks move because there is no legal last move for black - in chess960 or standard chess. When black starts he has several different options (castling is one of them) but white can checkmate against all of them!