Step into an O’Neill cylinder, a rotating space habitat with synthetic gravity, window bands to the stars, and whole cities curving overhead. Part one of the tour; save and share if you want the outside run along the mirrors next. #oneillcylinder #spacehabitat #megastructure #spacetok #scifi #hardscifi #worldbuilding #futurearchitecture #orbitalengineering #spacecolonization #syntheticgravity #spacesettlement #deepspace #futurism #conceptdesign #visualstorytelling #spaceart #cosmos #astronomy #engineeringlife #stellarwonders