As Brooklyn’s Grand Army Plaza and its memorial arch come into view along Flatbush Avenue, no one who loves Paris’s Arc de Triomphe and the Place de l’Étoile is immune to a lift in spirit. The Brooklyn Public Library also echoes Paris and the moderne-style Palais de Chaillot on the Place du Trocadéro with sleek lines, gilt, and all. The connections between the striking façade of the library and the Brooklyn plaza are even more felicitous now due to a recent renovation that has replaced a grand staircase with a new plaza that descends gently to the main one.

Along with Polshek Partnership Architects’s entrance façade for the nearby Brooklyn Museum and Richard Meier’s 15-story glass residential tower, On Prospect Park, rising across the street, the library’s important architectural additions, including an underground auditorium for cultural events, are contributing to the reanimation of the neighborhood and the institution itself.

“No longer a place simply to borrow books,” the library’s executive director, Dionne Mack-Harvin, said, “libraries now serve as cultural centers and as the most accessible public spaces outside of public parks where community groups may gather.” With these goals in mind, along with the needs of the electronic revolution, the Brooklyn Public Library has reshaped its mission, as well as its premises, without losing its focus on literature and the borough’s social history.

Although the library was completed in 1941, the architects Alfred Morton Githens and Francis Keally worked around the preexisting foundation and steel structure of an earlier Beaux-Arts design by Raymond F. Almirall that had been held up by politics and budgets. Designed in unadorned Indiana limestone, the building resembles an open book with two wings that slant toward a central spine, which is the main entrance facing Grand Army Plaza. Two concave columnar forms with gilt reliefs of figures symbolizing the arts and sciences flank the entrance — with Athena and her wise owl at the top — and 15 panels in bronze over the doors depict storybook characters. Not only does the structure look like a book, it reads like one as well with inscriptions by Shakespeare, Horace, Henry David Thoreau, and a multitude of others, inside and out, that are meant to inspire at every turn.

In designing the library’s new granite entrance plaza, architect Vincent Benic — working with landscape architect Signe Nielsen — has created a public platform that serves in balmy weather as an outdoor performance space and as a café (offering free wireless Internet access) that will seat 200 people by next summer. Flanking the shallow steps, bubbling jets of water flow down the slope as a visual extension of the 1932 Bailey Fountain across Grand Army Plaza. With attractive lampposts and high granite walls, the new fully accessible plaza has retained for the library its monumental stance while opening it up to the surrounding area including Prospect Park.

In a collegial gesture, the Brooklyn Botanic Garden has provided its sister institution with arrangements of flowering plants and grasses in freestanding planters at the plaza’s bottom edge. And in the surrounding grounds, Ms. Nielsen replaced trees that were removed for construction with fragrant Japanese lilacs and zelkovas. For ground covers, she selected low-maintenance creeping lily turf and purple-leaf winter creepers, and to conceal the bicycle racks on one side, winterberry shrubs.

The second transformation, equal to the first, is the Dr. S. Stevan Dweck Center for Contemporary Culture, the new auditorium and foyer in a space formerly occupied by staff offices and general storage. A Brooklynite now living in California, Dr. Dweck donated $1.5 million toward the library’s renovation. With its own side entrance at street level to a ticket office, this theater has a spacious foyer for intermissions and greenrooms that double as meeting rooms for local groups. In a palette of dark wood paneling with green ultrasuede seats for 200, the auditorium is intimate with an ample stage for musical or literary events. A forthcoming weekend, for example, will include a panel discussion about Brooklyn and the Civil War and how artists represented it. The weekend will also feature a program by the Brooklyn Philharmonic of popular songs from the era (November 10 and 11).

In harmony with tradition, four new inscriptions have been carved into the paneling on either side of the stage, with one by Henry Wadsworth Longfellow seemingly a motto for the project’s goals: “Let us, then be up and doing, / With a heart for any fate; / Still achieving, still pursuing, / Learn to labor and to wait.” Judging from the enthusiastic community response, the wait will not be long.