Superman: The Bottle City of Kandor #1

While on an experimental rocket, Clark and Lois encounter the alien Brainiac, who plans to shrink and bottle the great cities of Earth and then use them to repopulate his planet. Superman gets inside Brainiac’s ship when the villain snatches Metropolis and there finds a bottle with the Kryptonian city of Kandor. He enters the bottle and with the help of a scientist there restores the cities of Earth while Brainiac lies in suspended animation for his trip home. Because there is not enough power to restore Kandor, Superman places the city in his Fortress, as Brainiac rockets away empty-handed.