Two cities dominate the polder region-Amsterdam, the capital, and Rotterdam, Holland's greatest seaport. Amsterdam, originally a fishing settlement beside the Y, a gulf of the Zuider Zee at the mouth of the little Amstel River, became one of Europe's principal cities during the seventeenth century. Its colonial connections furnished one reason for its growth, and profits made in colonial trade are still the basis of its prosperity. With the decline of the power of the Dutch Republic, Amsterdam's glory was also for a time eclipsed, and its rise during the nineteenth century was restricted by harbor conditions unsuitable for modern trade. The Zuider Zee was too shallow for big seagoing vessels; a canal extending northward was too long to be successful; and it was not until the straight, short North Sea Canal was built that the problem was solved. At the seaward end of the canal, the great locks at Ymuiden, the largest in the world, have a depth of 40 feet, while the Y, now closed off from the former Zuider Zee, has become an excellent harbor.
The present trade is still typically colonial. Amsterdam imports tobacco, copra, coffee, tea, rubber, quinine, kapok, tin, spices, cocoa, teak, and the like. For some of these, especially tobacco, quinine, kapok, and pepper, it is the chief European market. A very special local industry is that of diamond cutting and polishing. Amsterdam and Antwerp supply the world market in this field. A canal connects Amsterdam with the Rhine and so gives it a share of the Rhine trade, although this is of small importance compared with the similar trade passing through Rotterdam. The Amsterdam stock exchange, the largest in Holland, distinguishes this city as the financial center. With its 800,000 inhabitants, its strong hold on the Dutch colonial trade, and its prestige as the capital, Amsterdam forms a busy center of Dutch economic life. Unlike most cities it is surrounded by a broad expense of grassland, and only beyond this soft, damp area does one find the garden suburbs such as Hilversum on the nearby sandy upland to the east and Haarlem on the dunes to the west. Around Amsterdam, especially along the Y, the North Sea Canal, and the little Zaan Canal important manufacturing has developed under the combined advantages of ocean transportation and the neighborhood of a comparatively large market.
Rotterdam is quite different. Its position at the mouth of the Rhine with its vast economic hinterland has made it an international transit harbor rather than a purely Dutch terminus. The canal known as the New Waterway provides easy access from the sea to the city, and all along both the canal and the Rhine from the Hook of Holland to Rotterdam stretch busy communities which share the city's trade and industries. Grain, ore, timber, oil seeds, cotton, and petroleum are imported and reshipped on long barges which are towed in strings up the Rhine. Upon their return the barges bring coal, iron, steel, and building stone, partly for export. In addition to the transit trade Rotterdam also receives the greater part of the Dutch imports--even more than Amsterdam--although its colonial trade is not so important. Just as around Amsterdam, manufacturing plants of great variety border the New Waterway and the neighboring waterways, making Rotterdam a local, but nevertheless important, industrial center. So many ships frequent this port that it is one of the world's chief harbors. In contrast to Amsterdam, which has regular steamship services to India and South America, the trade of Rotterdam is largely borne in tramp ships, although there are also well-known lines to the Dutch East Indies and to the United States.
Among the other cities are Delft, Leiden, Utrecht, and Groningen. Each is not only an important market town but also has a wellknown university. All four are located near the border of the lowland, Delft and Leiden near the dunes, Utrecht and Groningen near the eastern sandy uplands, and their garden suburbs extend into the drier sandy region.