Design an open-air rooftop terrace inside a natural ice cave structure located in Antarctica, using the cave's ice formations as the main material for the walls, floor, and ceiling. The terrace should open to the outside, offering a stunning view of the surrounding frozen landscape, including ice formations and frozen waters. It preserves the natural texture and translucency of the ice, allowing natural light to filter in, creating a serene and ethereal atmosphere. The design should feel like an extension of the natural environment, blending seamlessly into the icy terrain while also providing a functional and inviting space for relaxation. Incorporate subtle, minimalist furniture elements that complement the cold beauty of the surroundings without overpowering it, ensuring that the view and natural ice surroundings remain the focal point.