FORT McNAIR on Greenleaf point anchors Washington's waterfront and commands the river approaches to the federal city. Before L'Enfant designated it as a military bastion, the fair and breezy spit of land between the Potomac and Anacostia rivers had held ropewalks and a cotton mill.

Long before Captain John Smith ever saw it, the site had served as a major Indian camp, notes historian Frederick Tilp, who has spent much of his life researching and exploring the Potomac region. The fort was the home of Washington Arsenal, the first one established (1803) by the federal government, and by 1826 also held the first federal prison. Somewhere on the grounds lies poor Mary Surratt, now generally regarded as innocent, who was hanged there and was buried in an unmarked grave along with three of John Wilkes Booth's co- conspirators in the Lincoln assassination.

The post, headquarters of the Military District of Washington, took its present name from U.S. Army General Lesley J. McNair, who along with hundreds of his troops was obliterated by American bombers during preparations for the Allied breakout from the Normandy beachhead. Fort McNair is an "open post," which means visitors are welcome, although the MPs at the gate may ask you to show identification and state the purpose of your visit.

It's well worth the trip simply for a jog or a stroll along General's Row, whose stately quarters overlook Washington Channel. The seawall near the point is one of the best bass-fishing spots on the river; worm-and-bobber anglers will generally be kept busy hauling in bluegills, catfish and carp.

Looming above the point is the vast National War College building, now known as National Defense University, where officers who've been picked as the top brass of tomorrow are sent to study war some more. It's a great gloomy place, but the effect is relieved by the surrounding golf course, a nearly flat and very simple but lovely nine-holer of the sort that can be played with two clubs and one ball.

Fort McNair also has a theater, swimming pool, PX, commissary and other neat stuff, but the price of admission is, you have to join the Army.