I Build a Tower in the Abyss

The eclipse tide came and the blue star shattered. Every twelve hours, the fog of the abyss rises from below, and the monsters in the fog tear all living things into pieces. The only safe zone is the land covered by "boundary markers". When Lu Yuan woke up, he found that he was abandoned in the ruins. There were still three hours before the next eclipse. No weapons, no shelter, no hope of survival. Then he heard the voice— [Abyss construction system has been activated] [Host major detected: Civil Engineering] [Generating the optimal solution...] While others were still surrounding the tent with wooden fences, Lu Yuan had already laid the stone foundation. While others were trembling in the eclipse, Lu Yuan's tower walls caused monsters to smash their heads and bleed. While others were digging a well, Lu Yuan's water diversion system had already irrigated hundreds of acres of fertile farmland. They say the abyss is invincible. Lu Yuan said, give me a blueprint and I can fill in the entire abyss. This is a doomsday farming epic that starts from a broken tower, builds a city, unifies the floating island, and expeditions into the abyss.