The base exists because someone went looking for the right water. A ship's captain, Félix Dufourq, carried out the studies that identified this sheltered, naturally deep stretch of coast as the ideal place to build. The Italian engineer Luis Luiggi designed the works, and on 30 November 1896 the facility opened under the name Puerto Militar, the Military Port. It was a project born partly in secrecy, set in motion by a decree of President José Evaristo Uriburu. In 1911 a French-owned railway, the Ferrocarril Rosario y Puerto Belgrano, laid a broad-gauge line connecting the base to the inland city of Rosario. The harbor took its present name in 1923. Stone by stone, quay by quay, a frontier anchorage became the spine of a navy.

As the Argentine navy grew, so did Port Belgrano. Through both World Wars, the fleet's heavy ships were docked here. During the Cold War, the base sheltered aircraft carriers. The shipyard has never stopped working, maintaining and refitting vessels and submarines decade after decade. Today the base anchors destroyers like the ARA Almirante Brown and ARA La Argentina, a squadron of Espora-class corvettes, amphibious and supply ships, a fleet of tugs, and the Antarctic icebreaker ARA Almirante Irízar. It does not stand alone. Close by lie the related arms of Argentine naval power: the Marines' camp, called Baterías, and the naval aviation air base at Comandante Espora. Alongside the quays stand a naval hospital, six military schools at the middle and tertiary level, a printing press that produces the magazine Gaceta Marinera, the Stella Maris parish church, a museum, and seven residential neighborhoods for the families of those who serve. It is a working community as much as a strategic asset, organized entirely around the sea.

One name echoes here above the others. The cruiser ARA General Belgrano made Port Belgrano her home for some thirty years. On 2 May 1982, during the Falklands War, a British submarine torpedoed her, and she went down with 323 of her crew. It was a defining tragedy of that conflict. Today a monument stands at the base, in front of the Sea Fleet Command, beside the very anchorage the cruiser used for three decades, honoring the ship and her 323 lost sailors. The war's shadow lingered in other ways. When a British Royal Navy patrol ship limped into Port Belgrano in April 2006 for repairs, it was the first time since 1982 that a British warship had entered the Argentine base.

The base's newest mission points straight up. On land ceded to Argentina's space agency, CONAE, engineers are building the Centro Espacial Manuel Belgrano, intended as the launch site for the country's home-grown Tronador family of rockets. The location was chosen for reasons the navy understood long ago: existing facilities, security already in place, ample open ground, and a coastal position well suited for launches into polar orbit. The goal is ambitious. Argentina aims to loft its first satellites aboard the orbital Tronador II from here, with the larger version targeted to fly around 2030, after a series of suborbital test vehicles proves the technology. The harbor that found the deep water in 1896 now reaches for the sky.