"Fugly."

"You left at Ringworld (tho' you mention Halo).  From the Larry Niven wikia:The "Ringworld" is an artificial ring about one million miles wide and approximately the diameter of Earth's orbit (which makes it about 600 million miles in circumference), encircling a Sol-type star. It rotates, providing an artificial gravity equivalent to 99.2% of Earth's gravity by way of Centrifugal force (fictitious). Ringworld has a habitable flat inner surface equivalent in area to approximately three million Earth-sized planets. The majority of the surface is land interspersed with shallow, freshwater seas. On opposite sides of the ring are two large deep saltwater oceans, placed in counterbalance to one another."