I have a world where I cleared a large space underground and blocked the games day light and put buildings underground with sun blocks. I also have buildings on the surface above the underground buildings. Ever since I added the underground part to my map I've been getting a lot more a bad lag spikes. Is my game lagging because of the underground part of my map? If s, is it possible I can reduce the lag spikes by filling underground back with grass and pretend like I never messed with clearing space underground? How effective would it be? Note this is happening to me on the xbox360, not the PC.