The bright lights of Philadelphia’s famed Boathouse Row — long one of the city’s signature nighttime sights — are going dark, at least for now.

Outlining a cluster of historic boathouses along the Schuylkill River near the Philadelphia Museum of Art, the twinkly lights reflect off the water and give definition to the unique architecture of each building. “It’s in some ways our postcard shot of Philadelphia,” explained Tara Rasheed of Fairmount Park Conservancy, as indelible as the Liberty Bell or the art museum steps in “Rocky.”

Starting Monday, though, the lights will be switched off and taken down as work gets underway on a $2.1 million replacement project. If all goes to plan, a new, upgraded lighting system should be ready for the winter holiday season.

The buildings store the long, slender boats used by rowing crews, and have wide garage-door-like bays that open onto ramps that slope down to the water’s edge. Many have steep roofs or Tudor or Victorian-influenced architecture, which are accentuated by the lights.

Strings of lights were first installed along Boathouse Row in 1979 ahead of Pope John Paul II’s visit to Philadelphia. LED replacements arrived in 2005. Since then, time, weather and wildlife have taken their toll, leading to regular outages.

“Wholesale replacement to a more robust and durable system made sense in terms of the budget,” said Rasheed, the director of capital projects at Fairmount Park Conservancy, a nonprofit that works with the city to support the public park system.

Boathouse Row traces its history to the 1800s as Philadelphians flocked to the river for recreation and the city emerged as a major center of rowing. It became a National Historic Landmark in 1987.

Bonnie Mueller, commodore of the Schuylkill Navy, an association of amateur rowing clubs in Philadelphia, said Boathouse Row occupies a unique place in the city — while its buildings are individually maintained by the clubs that own and use them, collectively they form “a very iconic and important public landscape.”

“We recognize the lights of Boathouse Row mean something to people, and we see that as a gift and a responsibility,” she said. “”We are incredibly confident and excited to get the project going and are looking forward to celebrating its completion by the end of the year.”

The new, programmable lighting system will have 6,400 individual LED lights with 16 million color combinations — think Eagles green on game day — mounted to a custom track that will help protect them against the elements.

A private donor supplied most of the funding for the lighting project, while the City of Philadelphia, which is responsible for maintaining and operating the lights, is contributing $600,000.

While the lights are dark, clubs will be able to do building repairs on areas that were previously inaccessible. One club is planning a roof replacement, according to Rasheed,

“It is so important for Philadelphians and for visitors alike to have this beautiful landscape,” said Philadelphia Parks and Recreation Commissioner Kathryn Ott Lovell. “It’s the image we think about when we think about Philadelphia. … We have to take great care to put our best foot forward and make sure the physical beauty of our city reflects the passions of our residents.”