It has a very prime location. It overlooks a park. It has a Fifth Avenue address. It was designed by Henry J. Hardenbergh.

No, it's not the Plaza Hotel, whose reopening for its 100th anniversary in October has been delayed a bit.

It's 186 Fifth Avenue, an attractive red-brick and terracotta building on the southeast corner at 23rd Street, across the avenue from the Flatiron Building and overlooking Madison Square Park, that is being partially converted to four residential condominium apartments.

In their superb book, "New York 1880, Architecture and Urbanism in the Gilded Age," (The Monacelli Press, 1999), Robert A. M. Stern, Thomas Mellins and David Fishman not that the building was an attempt by Hardenbergh "to bridge the gap between the area's commercial and residential scales."

"The Fifth Avenue facade was slender and incorporated a metal-framed oriel, rising to a pedimented gable roof; around the corner, the Twenty-third Street front was boldly scaled with its six-bay, double-height, extensively glazed, arcaded treatment and a skyline enlivened with six gables."

Hardenbergh designed the Queen Anne-style building for Western Union and its facade is incised with "W.U. 1883". It was one of more than 130 Western Union offices in the city and was connected by pneumatic tube to the company's headquarters downtown 16-18 Broad Street that was also designed at the same time by Hardenbergh and was one of the architect's first commercial structures.

The authors noted that "The Real Estate Record and Builders' Guide's correspondent, probably Montgomery Schuyler, found much to admire in Hardenburgh's design: 'The arrangement and the modeling of the openings emphasize the weight of the wall. The general aspect of the building is sober and quiet, with that sense of straightforwardness and naturalness which can only come from following out and giving expression to the actual facts of the building.' In his monograph on Hardenbergh, published thirteen years after the completion of Western Union's uptown branch, Schuler praised it as 'in its kind, one of the most successful commercial buildings we have, and its quaint picturesqueness is the more valuable for seeming to have come unsought from the most straightforward treatment of the problem....The treatment of the lower stage is especially ingenious,' and the oriel facing Fifth Avenue 'one of the happiest bits of our street architecture.'"

The architect had offices on the upper floors of the building.

The building has new double-pane Pella windows, individual climate control in the apartments, and a video intercom system. The four apartments have 2,385 to 2,418 square feet.

Walter & Samuels is the sponsor of the conversion and Jack Green & Associates is listed as the architect in the Department of Buildings' files most recently and Daniel Goldner Architects a couple of years ago.

The last remaining available apartment is on the fourth floor and has an asking price of about $2,750,000.