The old No.1 stadium at the US Open is about to be replaced by a second roofed arena at Flushing Meadows in New York.
Louis Armstrong Stadium hosted two decades of championship tennis, memorable matches on the court that often hid its inadequacies off it.
Rain would send spectators scattering, fleeing onto crowded concourses and toward cramped rest rooms - not anymore.
When the new Armstrong opens in August for the US Open's 50th anniversary, complete for the first time with day and night sessions, the US Tennis Association (USTA) believes its second stadium will be second to none.
Topped by a retractable roof, it's the final stage of a five-year, $US600 million ($A797 million) project that remade the USTA Billie Jean King National Tennis Center but never disrupted the tournament.
USTA officials showed off the progress of the stadium on Thursday under rainy skies, and it was comforting to know there were two arenas where they could keep the action going if faced with the same weather in late summer.
"Now with two stadiums with roofs, you know that if you've got a ticket to the US Open, you're going to see tennis, regardless of the weather conditions," USTA President Katrina Adams said.
The roof over the main Arthur Ashe Stadium has been operational since 2016, amid a transformation that has included a new Grandstand stadium and additional seats on outer courts.
Work began on the new Armstrong after that tournament. A temporary, 8500-seat Armstrong was constructed for last year's event, while work continued on the new $US200 million ($A266 million) Armstrong to seat 14,000 and about 95 per cent completed.
It will be the first naturally ventilated stadium of its kind with a retractable roof, as openings at the north and south ends allow air to flow through even when the roof is closed, which will take less than five minutes. Usually, some form of air conditioning is needed to cool a stadium when the roof isn't open.
The Armstrong schedule will feature three day-session matches for the first nine days of the year's final grand slam, and a night session with two matches for the first six days.
