Tenenbaum's Sanctuary

From BioShock Wiki

Bridgette Tenenbaum's Sanctuary (also known as Tenenbaum's Safehouse and Little Sister Safehouse) is one of the only places in Rapture which are almost completely safe; Splicer and trap-free. It is where Tenenbaum houses all of the former Little Sisters, supplying them with beds and toys.

After Jack kills Andrew Ryan and Frank Fontaine takes control of Rapture, the Little Sisters attempt to guide him away from the Security Bots which Fontaine has summoned to kill him. However, while crawling through a vent, he falls down a hole and blacks out.

He awakens in a bed, where Tenenbaum addresses him and tells him that she reduced the effects which Fontaine's mental conditioning had on him, but she wasn't able to rid him of all of it. After he comes to and stands up, Tenenbaum's figure can be seen behind glass, but little else of her office can be made out. From this point, Jack continues through the sanctuary, passing Little Sisters playing with various toys who comment in different ways depending on how the player has chosen to deal with them up to this point. If you've harvested only a few and/or saved most, if not all up to this point, of them, they will make positive comments, such as, when another Sister asks who Jack is, "He's the one that's going to save us all" or "He's the one that saved me." If the player has harvested more Little Sisters, though, they make decidedly negative comments. Either way, a Little Sister leads him out of the Sanctuary and lets him out to Rapture's sewers, under Olympus Heights.

It is speculated that Tenenbaum may have created the safe house after the New Year's Eve incident, allowing survivors to take refuge there until they could escape Rapture. However, this doesn't seem likely when Tenenbaum's generally apathetic personality is taken into consideration—apathy to anything but the Little Sisters, at least.