The main reason for visiting Disneyland during Halloween is the park-wide decorations, the costumes of both staff and guests, and most of all the Haunted Mansion. A great experiential ride anytime of the year, but during this season it is tricked out with the Nightmare Before Christmas theme. The attention to detail is mind blowing. We went on it twice (thank you Fast Pass!) But I could have gone multiple times more. I was glad when the ride stopped in the middle so I could take a look more closely at the decorations, exhibits and lighting effects. We got some pretty cool pictures.