Aquarium was the central correctional facility of Atlantis and was located very near the royal palace. Prisoners were given special tunics color coordinated to correspond to the nature of the crime for which they were imprisoned. Orange or gold tunics were given to political prisoners. Regarded as a low threat level, these inmates were generally sequestered in the minimum security wing of the prisoners. Inmates whose crimes involved physical violence were given blue tunics. Other colors include red and purple.
When a teenage Orin first came to Atlantis, he was apprehended by Atlantean guards and imprisoned because he bore the Curse of Kordax (being born with blond hair). There he met the political prisoner Vulko and caught a glimpse of his mother Atlanna. 
Years later, Orin, now known as the super-hero Aquaman, returned to Atlantis during a time when it was being invaded by a race of giant jellyfish. He was apprehended by the invaders' guards and placed inside Aquarium. Amongst those imprisoned at the time, were Atlantean loyalists who plotted to take back the city from the jellyfish. Aquaman rallied them together and they broke out of Aquarium.