500 years

     Twilight walked around the castle, a newly crowned princess and alicorn. Even after a few days, she was still getting used to her wings, flying or not. Just in case she was to live in Canterlot castle, she was exploring so she could know where everything was. So far, she had found several satisfactory bedrooms. While exploring one room, she noticed something odd. Part of the floor sounded strange when she stepped on it. Using her magic, she pried up the floorboards and found it was actually a trapdoor. One that had been enchanted so only an alicorn could open. Curious, she fluttered down (rather bumpily, but at the time she didn't care). There was only one, long, dark, tunnel. Cautiously, she lit her horn and headed down the corridor.