It was Governor Winthrop who put into one of his official messages this chunk of wisdom: "The best part of a community is always the least, and of that part the wiser are still less." Anterior to the Revolution, Boston was the largest and most important American city, then having twenty-five thousand inhabitants. Boston Harbor covers about seventy-five square miles, having various arms, such as South Boston Bay and Dorchester Bay, and the estuaries of the Charles, Mystic and Neponset Rivers, which enlarge the landing-spaces. The outer harbor has great natural beauty, increased by the improvements and adornments of buildings, the water surface gradually narrowing towards the city, and dotted with craggy, undulating islands, having long stretches of bordering beaches, interspersed with jutting cliffs, broad and bold promontories, and both low and lofty shores. The adjacent coasts are lined with villages that gradually merge into the suburbs of the great city. In this spacious harbor there are at least fifty large and small islands, and most of these, which were bare in Winthrop's day, are now crowned with forts, lighthouses, almshouses, hospitals and other civic institutions, several being most striking edifices, giving a pleasing variety to the scene. The splendid guiding beacon for the harbor entrance stands upon Little Brewster or Lighthouse Island, at the northern edge of Nantasket Roads. This is Boston Light, elevated about one hundred feet, a revolving light visible sixteen miles. George's Island, near the entrance and commanding the approach from the sea, has upon it the chief defensive work of the harbor, Fort Warren, about two miles west of Boston Light. Farther in, and near the city, off South Boston, is Castle Island, with Fort Independence, the successor of the earliest Boston fort, the "Castle," built by Winthrop in 1634. Opposite and about one mile northward is Governor's Island, containing Fort Winthrop. This island was originally the "Governor's garden," and Winthrop paid a yearly rent of two bushels of apples for it. These forts are nearly all constructed of Quincy granite, but none has seen actual warfare. Long Island spreads its high crags across the harbor, outside of the inner forts, and has a lighthouse on its northern end, while to the eastward is a low, rocky islet, bearing as a warning to the mariner a curious stone monument, known as Nix's Mate. It was here the colonists used to hang the pirates caught on the New England coasts. Upon Deer and Rainsford Islands are hospitals and reformatories, and upon Thompson's Island, which is fantastically shaped like an unfledged chicken, is an asylum and farm-school for indigent boys. Spectacle, Half Moon and Apple Islands received their names from their shapes.