BioShock is set during 1960, in Rapture, a fictional underwater dystopian/anti-utopian city.[31][33] The history of Rapture is learned by the player through audio recordings as he explores the city. Rapture was envisioned by the Randian business magnate Andrew Ryan, who wanted to create a laissez-faire state to escape increasingly oppressive political, economic, and religious authority on land. The city was secretly built in 1946 on a mid-Atlantic seabed, utilizing submarine volcanoes to provide geothermal power.[34] Scientific progress flourished in Rapture, leading to rapid developments in engineering and biotechnology thanks in part to the brilliant scientists that Ryan brought to the city. One such advancement was ADAM, stem cells harvested from a previously unknown species of sea slug, which were discovered by Dr. Bridgette Tenenbaum to have the ability to regenerate damaged tissue and rewrite the human genome. Tenenbaum joined with businessman and mobster Frank Fontaine to create the plasmid industry, which offered superhuman physical enhancements to its customers. Tenenbaum found that ADAM could be mass-produced by implanting the slugs in the stomachs of young girls ("Little Sisters"), taken from orphanages founded by Fontaine.