In a month, the former SF Mart building will be busy with Twitter employees. Nearly all 1,000 of them will occupy three floors in the 11-story art deco style building.
Twitter's CFO gave the mayor a tour of their new digs.
"Being right on Market Street, both its location and its scale are both really terrific and we love being close to City Hall and the beauty of the dome; so the building has a lot of things we like," Ali Rowghani said.
Miles of cable are being put in for rooms with open tables to hook up laptops.
There's a cafeteria -- they like to call it the "commons."
And a large outdoor space with synthetic turf and succulents and a view of the city will certainly be a favorite of many.
Twitter's move is expected to revitalize the area. It was the plan presented by Lee and endorsed by the Board of Supervisors.
By relocating, Twitter will receive a 1.5 percent city payroll tax exemption for the next six years.
"They have reminded us over and over again that but for that exemption and our signaling to them that we're really going to make a serious effort on reviewing the whole payroll tax, I don't think that they would have had the confidence to stay here," Lee said.
Another high tech firm, Zen Desk, has also taken advantage of that deal after moving to the mid-Market area. In recent weeks, other tech companies like Airbnb and online game giant Zynga announced they will not only stay in San Francisco, but expand.
"An ecosystem of companies sometimes forms around the first or second company that moves to an area and we think that is going to happen here," Rowghani said.
The other floors of the historic building are expected to be leased before the end of the year.