In 2002, instead of moving into Mayor Giuliani’s ground-floor corner office, Bloomberg turned the empty chamber upstairs—formerly the home of the Board of Estimate—into what’s now called the Bullpen. The enormous, newsroom-style office houses 50 of his senior staff and aides, three aquariums, and a cardboard helicopter. “I’ve never understood why anyone would want to seal himself off from the rest of the organization. In the Bullpen, there are no walls, no gatekeepers, and no communication barriers,” explains Bloomberg. (via An Inside Look at the Offices of Martha Stewart, Michael Bloomberg, Aby Rosen, Paul Rudnick, and More — New York Magazine)