The luxury penthouse apartment at Facebook's newest office building costs a whopping $42 million - take a look inside

Facebook just dropped $35 million to take over all 33 floors of commercial space at 181 Fremont, a mixed-use skyscraper that will the third tallest building in San Francisco upon completion in 2017. It's the social media giant's first outpost in San Francisco.

When Facebook and Instagram, which was acquired by Facebook in 2012, move into their new offices later this year, employees will share the 70-story tower with some well-heeled residents.

181 Fremont - the tallest residential tower west of the Mississippi River - contains 67 luxury condos, including a full-floor penthouse. The $42 million penthouse price tag makes it one of the most expensive listing San Francisco has ever seen. It hit the market in March and has yet to sell.

These renderings of the penthouse at 181 Fremont give us a glimpse inside.