Stained glass beauty at Jefferson Market Library

When you gaze at the castle-like exterior, it’s hard to imagine that this 1870s Romanesque courthouse-turned-library branch could be any lovelier on the inside.

It is. Head up the grand spiral staircase and into the main reading room. The whole way, you’ll be struck by enormous stained glass windows as beautiful as those in any church.

Designed by Charles Booth (who also created stained glass at Grace Church on Broadway and 10th Street), they mostly feature geometric patterns.

Then there are these Pre-Raphaelite beauties, forever illuminating that breathtaking staircase.

The women’s prison in the middle of the Village

It’s doubtful that today’s Greenwich Village residents would allow the city to put up a fortress-like jail behind Jefferson Market, the 19th century courthouse-turned-library at Sixth and Greenwich Avenues.

But the Village was different in the 1930s. When city officials decided to replace an old jail that was part of Jefferson Market, they weren’t met with NIMBY opposition.

So in 1932, the Women’s House of Detention opened.

Modern and bright (WPA murals lined the walls), it focused on reforming the inmates, often charged with prostitution.

There were some illustrious inmates, held for other crimes, like Ethel Rosenberg, Angela Davis, and Valerie Solanas, who shot Andy Warhol in 1968.

Longtime Village residents still miss the street theater: Inmates on higher floors catcalled men on the street and cussed out visiting boyfriends and husbands on the sidewalk below.

By the 1960s, it was overcrowded and as unsafe as the jail it replaced. Closed in 1971 (inmates were shipped off the Rikers Island), the building was bulldozed in 1974.

A lovely garden was planted in its place.