Manhattan oasis.

Located on New York's Upper East Side, the new Asphalt Green Aqua Centre forms part of a larger recreational complex arranged around a former municipal asphalt plant. The parabolic arched concrete clad steel structure, designed in 1942 by Ely Jacques Kahn in partnership with Robert Jacobs, is one of New York's most distinctive modern landmarks. Decommissioned of its original industrial function, it has been recolonised as a sports centre among a landscaped complex of parks and outdoor playing fields. To this sportif agglomeration has recently been added a swimming pool and fitness centre by Richard Dattner.

The new building occupies the northern point on the right-angled triangle of the site which is bounded on its hypotenuse by Franklin D. Roosevelt Drive and the placid surge of the East River beyond. The triangular configuration of the site informs the massing of the building. A 50m pool -- remarkably the first ever constructed in Manhattan -- is aligned parallel with Franklin D. Roosevelt Drive. This great volume forms the long side of the triangle, with ancillary accommodation compacted into an abutting five-storey wedge. To minimise encroachment on an existing playground, the wall of the ancillary wedge was designed to bulge at intervals, to accommodate the corner of the large pool and adjacent training pool. This strategic undulation has been extrapolated to become the building's main theme. The external envelope is conceived as a series of satisfyingly curvaceous brick and glass block walls, adorned in turn by sensuous, waving canopies and terrace sunshades.

Although the languid curves may recall the leisured streamlining of the 1930s, the building's array of facilities is incontrovertibly modern. The 50m main pool, training pool and changing lockers occupy the ground floor, with spectator seating, club lounge and membership office on the first floor. The curving tubular steel trusses over the pool hall are intended as a respectful contemporary homage to Kahn and Jacobs' gravity-defying parabolas. Inside, an aura of scrubbed health and sporting efficiency prevails, emphasised by the nautical white and blue colour scheme and the great flood of natural light drenching through the vaulted roof.

Far from being a one-use building, the new Aqua Centre is a hive of different, yet mutually compatible activities. The second floor of the ancillary wedge contains administrative offices for the entire Asphalt Green complex, while the third is devoted to a sports medicine facility operated by New York's Mount Sinai Medical Centre. This includes a small therapy pool, therapy rooms and rehabilitation areas. Above are facilities for general exercise, aerobics and yoga.

Space within Manhattan's restricted, finite grid is necessarily precious, and New Yorkers have become used to leaving their island in pursuit of recreation elsewhere. The Aqua Centre, with its enlightened mixture of sporting and therapeutic uses, is a literal oasis in the urban desert.