With 38,000 workers at more than 170 companies in 22 million square feet of buildings over 7,000 acres, Research Triangle Park is the largest research park in North America. And RTP isn’t just about its big corporate campuses—it has five buildings devoted to start-up ventures, and 60 percent of its companies have 20 employees or fewer. But today’s entrepreneurs, Mr. Geolas said in an interview, want more-inclusive settings where they can meet with one another, share ideas, find new workers, and just enjoy themselves.