Both sets of stairs will lead up to the roof. If you ask the staff, the door is locked and you shouldn't have any need to be on the roof of the hotel. However, if you actually try the door at the top of the stairs it will open just fine for you.

While it seems strange that the staff are telling you that you shouldn't be up on the roof - there's nothing to see on the roof. Everything appears as is what you would expect on a hotel roof - a few water tanks, a few satellite dishes to supply the rooms with tv, etc. There's even a fire escape slide down along one side of the building, even if looking at the building from the ground you don't remember seeing it before.

There is a spectacular view of the mountains and hills and the forest around the hotel now that you're up so high too. There will always be a dense fog behind the mountains and at the far edge of the forest, cutting off any view of distance city lights one might expect at night. But then, you should be looking skyward at night anyway, because the stars are bright and there's a hint of color that some nights flickers across the sky in a ribbon of shimmering lights. Almost like the aurora borealis, even if it's not quite scheduled that night.