Avalon 72 With its perfectly curved form and deep interior, this award-winning NativeStone concrete bathtub provides breathtaking beauty and optimum comfort. Avalon’s thick walls provide insulation to ensure that a hot, deep, relaxing soak will last and last. Avalon is handcrafted of a breakthrough combination of natural jute fiber and cement, by artisans who hand form, polish, finish and seal each individual tub using contemporary craft techniques.