Billionaire Leon Prater’s Mansion is actually a composite of three different New York locations (four, if you count his grand helicopter estate, which doesn’t show up until the 7th episode). •    The exterior of the house, •    This gated driveway and parking area,  and •    The interior of the mansion were all filmed at different locations around New York.

Q. What is it supposed to be on the show?

A. The gated entryway to a private parking area.
 

 
Q. Where is it supposed to be on the show?

A.  In Manhattan.

Q. When did we see it on the show?

A. We see this location in Episode 4 of Season 1 of Resurrection.
 
After Charley has picked up Dexter in Central Park, and driven him past the front of Leon Prater's Manhattan mansion, she pulls into this unique and very impressive driveway through a leading through a tunnel into an even more impressive parking courtyard . 

Charley parks her Mercedes and they get out. She leads Dexter to a door which leads to an elevator, which (after he uses a fake thumb print to verify his identity) takes them inside Leon Prater's mansion.  
 
 

A. The gated entryway to a private courtyard/parking area, known in the architectural trade as a “gated port cochere and motor court”.
 

A. This is actually the entrance to the parking area of the luxury condominium at 20 East End Avenue, in Manhattan.
 
This building is located on the southeast corner with 80th Street, near Carl Schurz Park, in the Yorkville section of the Upper East Side.

Here is a wide- angle image of the entire courtyard, from a real estate listing:

Here is a matching StreetView of 20 East End Ave:

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Here is an aerial photo of the location.  And here is a map link.

( It should be noted that this parking entrance is not on East End Ave. That's where you'll find the main entrance to the building. Instead, since this is a corner building, this parking entrance faces E 80th Street, and maps to around 535 E 80th Street. )    

Here is a blow-up of this entrance, as it appears on Google StreetView:

 
Now here is that same photo, only lightened  & enhanced in PhotoShop to bring out the details: 

And see how perfectly it matches the screencap from that scene:

Although it looks like this spectacular locale may have been around for ages, it was actually just built in 2017.

Inspired by the style of the 1920s, and located near the East River, the building is 17 stories tall, with 43 luxury units  and two penthouses.

Here is a short video of of 20 East End Ave.

Here's what Wikipedia has to say :

“East End Avenue, on the eastern edge of the Upper East Side, has long been home to some of the city's richest residents, including Vincent Astor and Gloria Vanderbilt.

An entry-level, two-bedroom apartment was initially priced at approximately $4.5 million and one of the two penthouses at $39 million.

The building is the last in New York City to incorporate wood-burning fireplaces after New York City banned new ones in 2014. Other amenities include a gym, library, billiards room, poker room, 9,000 bottle wine cellar, private dining room, spa, kid's playroom, and storage facilities.”

( It appears that, as of 2025, the nThere you go on-penthouse units currently go for around $7 to $15 million. )