I just finished my best, hardest fought civ game ever. I'd done one city challenge games before, but I'd never managed to win one. I was playing on monarch, pangaea map, so I knew that I'd have to keep the AIs at war in order to keep up in tech. Unfortunately, I had no oil in my city limits (although there was one 1 square outside!), so I had to keep it out of their hands as well, in order to keep them from crushing me with tanks.

Originally I had been going for a conquest victory, but this was impossible because two AIs had settled on islands, and I couldn't build votes. So, I switched to a spaceship goal. By the time I got rocketry, I realized that there was not enough time for me to finish a spaceship. So i had to resort to building the UN, and nuking the enemy islands about 20 times, until their population was low enough for me to win.

I had a close OCC with a space ship win with 1 turn left. Thankfull, I had a PA with Cyruse and he cooperated with me by only researching space ship techs and helping me build them, I had lower production then normal.