Catch up TV on Megastructures. Watch the latest and all other episodes of Megastructures now online, broadcast on 7Two. Catch up on your favorite 7Two TV show: Megastructures. Replay tv on its best! Take an eye-popping look at the greatest structures and machines ever created as we focus on some of the world's modern-day super-human miracles of construction. Each episode is an educational look of varying depth into the construction, operation, and staffing of various structures or construction projects, but not ordinary construction products.