It's one of New York's iconic buildings, but until Tuesday the Cathedral Church of St. John the Divine was not a city landmark. Our Michael Scotto tells us why.

"Most people who walk into this cathedral are really shocked by size of it," said Rev. Patrick Malloy.

The Cathedral Church of St. John the Divine is two football fields long, making it one of the largest church buildings — and the largest cathedral — in the world.

It is known for its seemingly endless nave or center aisle, massive stone columns that soar to the ceiling, and vivid stained glass.

"The building as a whole is a sort of a witness to the birth of the gothic revival," Rev. Malloy said.

Now the 125-year-old cathedral has another distinction: it is a city landmark, a designation granted by the Landmarks Preservation Commission on Tuesday.

"It has this unique history to it which is of craftsmanship and artisans, building and working in the area," said Meenakshi Srinivasan, Chairman of the Landmarks Preservation Commission.

Efforts to landmark St. John the Divine started years ago. Back in 2003, the commission had voted to landmark the building, but the City Council rejected the move. 

That's because at the time local officials wanted to see the entire site — not just the cathedral — landmarked, fearing that the church would lease the land to developers. That's exactly what happened, and today new apartment buildings stand on the north and south sides of the property.

"We do need the income, and I think if you look across the city, most cultural not-for-profit organizations are seeing the sort of pinch that we are," Rev. Malloy said.

With those buildings constructed, the church agreed to landmark the entire site. Area residents, while pleased it will finally be protected, complain the designation came too late.

"We are very unhappy with what went before it to create such a scar on the property of that cathedral," said Laura Friedman, president of the Morningside Heights Historic District Committee.

Now that it is a landmark, church officials will have to seek city approval the next time they want to alter the iconic institution.