The Fortress of Solitude, a sanctuary on Earth for Krypton's Last Son. The magnificent crystalline structure was quite unlike anything built by human being. It was distinctly alien, much like Superman himself. The Fortress was everything the Bat-Cave was not. While Batman's lair was dark and utilitarian, Superman's sanctuary was bright, vibrant and beautiful. As it sparkled in the sun Clark wondered if it somehow drew strength from the same source as he. 

The Fortress was originally the ship that had brought Clark to the Earth as a baby, but as he grew, it did as well. When he entered adulthood, his ship came alive, blasting away from it's resting place on the Kent farm and heading north, far, far away from the populated world. Through advanced Kryptonian technology the ship expanded itself and terra-formed the land around it, building what would become the Fortress of Solitude. What began as a cradle for Clark as an infant would become a home for him as a man. 

In the main chamber, there was a massive Kryptonian computer. Clark placed the arrow underneath the computer scanner, hoping to collect a data-reading from it. According to the computer, the robot's origin was indeed the planet Colu, as was reported by Green Lantern's ring. It's configuration and specifications matched that of Coluan probe droid, controlled by an entity known as Brainiac. After pondering for a moment, Clark placed his hand on one of the computer panels, which began to glow. 

"I am in need of your help Father."

A massive hologram projection appeared in the image of Jor-El, Superman's biological father. 

"Speak my son."

"My world has fallen under attack," said Superman, "A Coluan probe droid came to Metropolis, sent by a being known as Brainiac. However, I have not heard of such a planet, nor have I encountered such a being."

"I had feared this day would come my son," replied Jor-El, his voice booming through the halls of the Fortress, "The Earth has been chosen by the Preserver of Worlds." 

"Preserver of Worlds? I don't understand."

"Brianiac," replied Jor-El, "Is an immensely intelligent and highly advanced android, whose primary function is to collect and preserve remnants of doomed civilizations."

"You speak as though you have seen this android before..."

"I have Kal-El. Decades ago, he came to the planet Krypton," Jor-El paused before continuing, "His forces invaded our world, but his aim was not to destroy it. He miniaturized our greatest city, the City of Kandor, and collected it in a bottle. A relic of a doomed world. The bottled City of Kandor is all that remains of Krypton, aside from this Fortress, and you."