The Citadel is a massive, technologically advanced deep space station from alien origins (even to aliens) that serves as the political, cultural and financial capital of the galaxy in the "Mass Effect" video game series. It's also a trap for space-faring civilizations so that Lovecraftian aliens can commit galactic genocide every 50,000 years. That horrifying thought aside, the Citadel's five arms contain the "Wards," where a bulk of the commercial and residential centers are. The Wards brim with skyscrapers behind the view of the spectacular Serpent Nebula, streamlined air transport (or long elevator rides) and no artificial day-night cycles to facilitate nonstop commercial activity. For a spectacular view in the hot seat of galactic civilization and events, the Citadel is the place to be!