A megaring is a galactic megastructure shaped similarly to a ringworld, but significantly larger, constructable with significant effort by a Type 3.0 Civilization and routinely by a Type 4.0 Civilization and above. They have a radius of 10 light years, and spin to provide artificial gravity. Around 330 solar masses are used for the structure of the megaring, which can then be filled with 3130 solar masses of air, and 126,000 solar masses worth of stars orbiting the megaring and held in place to provide heat and light. They require around 1045 to 1046 joules to assemble.