Mine is what you frequently see in games like Tomb Raider, Uncharted. You spend an entire questline finding keys, solving puzzles, avoiding deathly traps to open the door to a secret ruins that has been undisturbed for thousands of years...
Then you get inside and you look up and it's COMPLETELY OPEN TO THE SKY. Like enough to see from the air and to land a helicopter in open.
Never mind how unrealistically good these characters are at climbing anyway, but nooo we couldn't possibly come in from the top.