Texas Subcategories This category has only the following subcategory. S Space habitats (9 P) Pages in category "Proposed arcologies" The following 21 pages are in this category, out of 21 total. This list may not reflect recent changes. ArcologyA Aeropolis 2001 ArcosantiB Bionic TowerC Cloud Nine (sphere) Crystal Island (building project)D Dome over Manhattan Downtown CircleF Freedom ShipL The Line, Saudi ArabiaM Millennium Tower (Tokyo)O Old Man River's City projectP PhalanstèreS Seascraper Seward's Success, Alaska Shimizu Mega-City Pyramid Sky City (Changsha) Sky City 1000T Times Squared 3015X X-Seed 4000Z Ziggurat Pyramid, Dubai