Open House New York officially starts Friday and runs through Sunday across the five boroughs, allowing free access to more than 300 locations that either charge admissions or are normally off limits to the public.

Among the places making the list this year is the Brooklyn Seltzer Museum in Cypress Hills.

"We do it the same we've been doing it since my grandfather since 1953 when my great-grandfather started the business," said Alex Gomberg, the third generation of Brooklyn Boys Seltzer, a longtime business that houses the museum. "It's a great experience for you to see how the seltzer is made manufactured, the history of seltzer, the science of seltzer."

Another place opening its doors for free this weekend is the New York Sign Museum in East New York.

"The oldest signs we have are from the 20s," said Seamus Seery, New York Sign Museum. "It's mostly businesses around Manhattan, Brooklyn and Queens."

Visitors can learn why NYC signs are different from those in other cities.

Other places in Brooklyn that made the list include the Brooklyn Army Terminal and go canoeing on the Gowanus Canal.

In the Bronx, the Edgar Allen Poe Cottage, New York Botanical Garden and the New York Latin American Art Triennial at Bronx Art Space are participating.

Some locations require reservations.

To see the full list click here.