New York City Mayor Bill de Blasio and his team have revealed the designs for the 250,000-square foot Union Square Tech Hub.

The hub, which was first announced in December, will include 58,000 square feet of “fluid space” for startups and a 36,500-square foot tech training center. (Partners in the training program include the New York City Foundation for Computer Science Education, General Assembly, Per Scholas, FedCap, Code to Work and Coalition for Queens.)

The anchor tenant will be Civic Hall — a 1,000-member work and event space that focuses on what founder and CEO Andrew Rasiej said is “the idea that technology can be used to support the public good.

De Blasio unveiled the designs at an event this afternoon at the New York City headquarters of adtech company AppNexus, where he also talked about his hopes for the space.

After praising NYC’s tech community for being “the most diverse tech community in the country” and “the most socially conscious tech community in the country,” de Blasio said the hub is about “making sure more and more New Yorkers benefit from this extraordinary tech ecosystem.”

“It’s about protecting democracy,” he added, prompting a loud round of applause. “I think you were able to infer my meaning. There is a fervent passion for ensuring an openness of information and debate and inclusive society. What we’re doing with this beautiful hub will be a part of that.”

As the name suggests, the hub will be located in New York’s Union Square, in the location currently occupied by electronics store PC Richard & Sons. The plan is to start construction in 2018 and open in 2020.