What does Brooklyn’s industrial waterfront have in common with El Camino Real de Tierra Adentro National Historic Trail in New Mexico? Or with the Hialeah Park Race Course in Florida? All three appear on the National Trust for Historic Preservation’s 2007 list of the 11 most endangered historic sites in America . Brooklyn’s industrial waterfront , a once-mighty concentration of factories, warehouses, railways, and shipping facilities, ranges south from Greenpoint to Sunset Park. Greenpoint and Williamsburg, following a 2005 rezoning, represent a particularly endangered swath of historic waterfront.

This summer may offer the last best opportunity to view parts of the waterfront in the midst of its transition from a gritty industrial environment to phalanxes of tall residential towers with riverfront esplanades and the occasional park. The L train penetrates to the heart of Northside, epicenter of Williamsburg’s dramatic, and rapidly outward-spreading, gentrification. A short walk from the Bedford Avenue station along North 7th Street takes you to the waterfront, at Kent Avenue, where you’ll find, on the left, the new luxury development called Northside Piers and, on the right, the new East River State Park.

The words “state park” conjure visions of pristine Adirondack trails. In Williamsburg we have something different: A few acres of, in my view, underdesigned and undershaded — whether deliberately or not, it’s hard to tell — land between the site of a future mega-development called the Edge and the site of a future city park. The city has seven other state parks: two in Queens, one in the Bronx, one on Staten Island, two in Manhattan, and one in Brooklyn.

East River State Park opened in May. (Because of problems with sodding taking hold, the park’s opening occurred a year after originally planned.) At first, the state announced that the seven-and-a-half-acre park, developed with the Trust for Public Land, would be open only on weekends. The weekends-only policy angered local residents, who had looked forward to the park as a respite from the unyielding construction that has rocked the area for the last couple of years. Williamsburg and Greenpoint residents have shockingly little public access to their waterfront.

Apparently responding to local discontent, the state rescinded the weekends-only policy to one of seven-day access that began last Tuesday.

The park sits on a site formerly part of the Eastern District Terminal, a node in the Rube Goldbergesque network of dock and railway facilities that once dominated the Brooklyn and Manhattan waterfronts. The terminal began in the 1870s and received the Eastern District (once a commonly used moniker referring to Williamsburg, Greenpoint, and Bushwick) name in 1906. Barges and carfloats came from New Jersey, Staten Island, and the Bronx. Major docks operated between North 4th and North 10th streets. The park occupies the waterfront between North 7th and North 9th. To the south, Toll Brothers’s Northside Piers, which has been rising rapidly to its 30-story height, stands between North 4th and 5th streets. Douglaston Development’s forthcoming the Edge (with nearly a thousand apartments), between North 5th and North 7th streets, occupies old carfloat docks where the Eastern District Terminal interchanged with the New Jersey Central, the Erie-Lackawanna, the Baltimore & Ohio, the Pennsylvania, the New York Central, and other railroads. Waterfront trains carried supplies, raw materials, and manufactured goods to such vast industrial facilities as the Domino sugar refinery and the Austin, Nichols food warehouse. Declining industry and the port’s reconfiguration following the postwar introduction of container shipping, as well as the city’s disinterest in retaining the waterfronts for industrial uses, caused the terminal to close by 1983.

With the Edge yet to rise, Northside Piers’s siting affords a lovely vista of the Austin, Nichols warehouse, and, beyond it, the Williamsburg Bridge from the new park. (Oh, there’s this tremendous view across the river to Manhattan , too, if that’s your thing.) The Toll Brothers development may tower over Williamsburg (though soon it shall be but a tree in the forest), but if anything it — and everything else going up in Williamsburg — brings out even more of the beauty of the warehouse. The Landmarks Preservation Commission designated Austin, Nichols in 2005, but the City Council, led by mercurial David Yassky, overturned the designation. Now’s the time to visit the new park, and to see Cass Gilbert’s marvelous 1913 warehouse before its majesty — and that of Brooklyn’s industrial waterfront — yields to the towers’ glassy sheen.