Create a hauntingly beautiful scene featuring a phantom castle standing atop a mist-covered mountain. The castle is shrouded in mystery, with its ancient stone walls and turrets partially obscured by swirling fog. Inside, dimly lit corridors echo with silent whispers, and ghostly figures barely visible in the shadows. The atmosphere is eerie yet captivating, with a blend of gothic romance and supernatural elements. Use soft, ethereal lighting to enhance the mystical ambiance, and incorporate lush, overgrown gardens and ancient trees around the base of the castle to add depth and texture to the environment.