Tucked away beneath an elegant and striking block in Hamilton Heights, there’s a rarely seen hallowed space carved from rough stone with perfect acoustics and history thickly hung from every rafter. Simply known as the Crypt, it is a hidden gem of New York City owned by the Church of the Intercession.

A select group of about 50 people gathered together recently to witness the wonder of John Holiday, a counter-tenor whose voice is as magical as the Crypt itself. Here are five secrets about the Crypt and its surrounding property:

5. The Crypt Is Home to a Limited Run of Classical Concerts

Get your fingers ready to hit refresh on your laptop or phone with record speed. That’s the kind of agility (and luck!) that it takes to score a ticket to the Crypt Sessions. The brainchild of Andrew Ousley and his team at Unison Media, the Crypt Sessions feature classical musicians on the forefront of keeping the art form relevant for today’s audience.

Holding these concerts like the recent one with John Holiday in an intimate and limited access location provides a sense of mystery that matches that thrill of discovering an artist on the precipice of wide-spread fame. The audience members for Holiday were so moved by his music that they alternately laughed, cried, and sat awestruck by his artistry and passion during his varied program of new opera, spirituals, and jazz standards.

Anywhere, this music would have been a treat to hear. Inside the Crypt, the performance took on a mystical quality that left audience members wondering afterward, “Did that actually happen?” Learn more about the Crypt Sessions and their new concert series, The Angel’s Share, in the catacombs of Brooklyn’s Green-Wood Cemetery at deathofclassical.com.

4. John James Audubon Found his Final Home and Resting Place Here

The Crypt is accessed through the Trinity Church Cemetery surrounding the Church of the Intercession. This cemetery and the surrounding blocks served as the homebase for John James Audubon, the naturalist and artist known for his work in ornithology (the study of birds).

Audubon’s original home at 765 Riverside Drive (at 157th Street) is no longer there. However, the area is still known by many as Audubon Park, and there are several stunning and colorful larger-than-life murals on buildings surrounding the Church of the Intercession that feature Audubon’s beloved birds.

Audubon is buried in Trinity Church Cemetery and there is a large imposing monument erected there in his honor. Alfred D’Orsay Tennyson Dickens, the son of Charles Dickens, author Ralph Waldo Ellison, Mayor Ed Koch, Hercules Mulligan of Hamilton fame, and actor Jerry Orbach are buried there, too.

3. Our Traditional Conception of Santa Claus Is Commemorated Annually at this Church

What’s the oldest, continuing Christmas tradition in New York City? The Rockefeller Center Tree? The window displays at Macy’s? Not even close. It’s a festival at the Church of the Intercession known as the annual Clement Clarke Moore Festival. It honors the writer and professor who is widely credited with writing “A Visit from Saint Nicholas”, known more popularly as the beloved poem “‘Twas the Night Before Christmas”. The festival has been held for over 100 years on the Sunday before Christmas at 4pm.

The idea of Santa as a jolly old elf with reindeer is largely attributed to Moore. Rumor has it that he wrote the poem while living in his home in the Chelsea neighborhood of Manhattan. The rumors of how the poem came to be are quite elaborate: the scene was allegedly a snowy winter day in 1822. Moore was dashing through the snow-filled streets of Chelsea in his sleigh on his way to pick up a turkey when the poem just magically came into his imagination as a gift for his two young daughters. Moore later said the inspiration for the physicality of Santa Claus in his poem was one his neighbors, an immigrant from Holland.

The poem was published, anonymously, in 1823, and some time in the 1830s, Moore was finally revealed as its author. Like Audubon, Moore is buried at the Trinity Church Cemetery (and perhaps keeps a watchful eye from the beyond on the festival that bears his name!)

2. Third Time’s a Charm in Architecture

The gothic architecture of the Church of the Intercession is so imposing that it seems like it’s been there forever (or at least a few hundred years)! It is actually the third building to occupy this space. The first building was a wooden structure completed in 1847. Then, in the late 1800s, a stone church was built. Finally, in 1912, the cornerstone for the current church was set and the church was completed in 1915.

It’s widely thought to be the finest example of Gothic Revival style architecture in the city and is part of the National Register of Historic Places (a division of the National Park Service).

1. But Are There Really People Buried in the Crypt?

Yes. Yes there are. In the 1920s, cemetery space in the city was scarce and in high demand. To accommodate for this, the Crypt’s walls were prepared to hold cremated remains and with that it became the first church in the U.S. to have its own columbarium (a building with niches for storing funeral urns.)

The Crypt at the Church of the Intercession isn’t the only crypt in town. Check out this piece about the Saint Patrick’s Old Cathedral on Mulberry Street.

Next, check out Trinity Church’s Four Cemeteries in NYC and see What NYC’s Former Cemeteries Are Now.