Ring 1: Limbo, where it consists of a group of sky islands floating way above the surface. The atmosphere is ethereal and tranquil. This Ring contains a wide range of towers which spreads fairly across the difficulty chart. The center island contains a sustainable lobby, equipped with ventilation, snacks, and other stuff. (unfortunately I can't list each Towers here due to character limit, so look up official EToH Wiki on the Ring 1 page)