BUT THE MONEY SEEMS TO HAVE BEEN SPENT: NYC never opened 25 planned preschools despite demand surge — and may not have even known one existed.

Roughly 20 planned early childhood education centers in the Big Apple mysteriously sit idle as demand surges for universal pre-K and 3K seats close to home, The Post has learned.

More than 25 of 47 3K “initiative projects” at sites first earmarked under former Mayor Bill de Blasio are still unlisted on the official NYC MySchools directory — despite costly construction contracts, rent payments to private owners and official Department of Education signage posted outside some “phantom” schools.

The list of leased shell sites includes a converted Brooklyn warehouse on the Columbia Street waterfront — where nearby young families face waitlists of more than 100 students for a nearby seat, parents told The Post.

Exit quote: “If we’re paying for the school to be built and it already exists, it’d be great to be using that school.”