For the past nine years, Nicole Gulmi, 34, who works in sales at Bloomingdale’s in Melville, N.Y., has attended the United States Open tennis tournament with her mother.

It’s a special treat, so they usually splurge on tickets to Arthur Ashe, the largest stadium featuring the biggest matches. But this year, instead of using their Ashe tickets, the mother/daughter duo spent their time in another stadium: Louis Armstrong.

Armstrong’s completion was the last stage of a five-year, $600-million-dollar renovation of the U.S.T.A. Billie Jean King National Tennis Center, in Flushing, Queens. The brand-new stadium has a retractable roof and is naturally ventilated, featuring overlapping terra cotta panels that circulate the air between decks.

While you must have a ticket to sit in Armstrong’s lower seating, the top bowl and all of its decks are open to those with grounds passes or tickets to Arthur Ashe. There are stunning views of the Unisphere and Citi Field. The stadium seats approximately 14,000 fans, but it feels strangely intimate. Play was halted twice on Monday, the first day of the tournament, during a match between Andy Murray and James Duckworth because some fans didn’t sit quickly enough at the end of a break, disturbing the players.