Fish Gear Sunken Ruins Aquarium Ornament;. Transform your aquarium or reptile terrarium into a sunken ruin with our Fish Gear Sunken Ruins Aquarium Ornament. Crafted with detailed design and safe for all aquatic environments, add a touch of adventure to your tank while providing a new hiding spot for your fish or reptile friend. Available Sizes (Approximately): Small: 8 cm base x 9.5 cm height Medium: 19 cm base x 12 cm height