Corinthian columns. On the original second floor, the second bay from west is flanked by oval windows on either side, while the third bay from west is an oriel window. Within the 1888 extension, the first floor contains a projecting three-sided bay supported by pilasters and flanked by carved panels, as well as a blind arch opening to the east. The second floor of the extension contains paired window openings flanking a smaller triple window, while the third floor contains paired windows on either side of an oval window. The cornice above the third floor, as well as the attic, in both the original house and its extension is similar to that on Madison Avenue. The southern facade of the house faces the rest of the library and is mostly obscured behind the 2006 addition. The westernmost portion of that facade, near Madison Avenue, contains rounded first- and second-story windows. There are also three-sided angled windows at the center of that facade. Entrance building The most recent addition to the library, completed in 2006, is a four-story, steel-and-glass entrance building designed by Renzo Piano and Beyer Blinder Belle. The entrance building expanded the Morgan Library's area by . The structure links McKim's library building, the annex, and the Phelps Stokes/Morgan house. There are four galleries in this section of the museum: the Clare Eddy Thaw Gallery, the Morgan Stanley Galleries West and East, and the Engelhard Gallery. The steel structural members are covered in rose-tinted paint as an allusion to the designs of main library and Phelps Stokes/Morgan house. Although externally "bland", the building helps to organize the interior spaces of the complex. The entrance building contains the JPMorgan Chase Lobby just inside the main entrance. On the lobby's north wall, stairs lead up to the Morgan Shop and Morgan Dining Room, and there is an admission counter and coat room. The south wall has a corridor to the Marble Hall and the Morgan Stanley Galleries West and East, as well as stairs to the Engelhard Gallery on the second floor. The east wall of the lobby has a stair to the lower level as well as elevators to both the Engelhard Gallery and the second level. Gilbert Court, a covered courtyard at the center of the complex, surrounds the entrance building on the north, east, and south. On the south wall of the court is the Clare Eddy Thaw