The Dutch arrived here first, building a wooden wall at the edge of their small settlement to protect themselves from pro-British settlers to the north: hence the narrow canyon of today's Wall Street gained its name. It's here, behind the thin Neoclassical mask of the New York Stock Exchange, that the purse strings of the capitalist world are pulled. Take a long look at the mythological figures on the building's pediment: when the original stone figures began deteriorating in the Manhattan air, the Exchange clandestinely replaced them with these virtually indestructible sheet-metal copies, for under no circumstances was any aspect of vulnerability to be associated with the Exchange.

From the Visitors' Gallery (Mon–Fri 9.15am–4pm; free), the Exchange floor appears a mêlée of brokers and buyers, all scrambling for the elusive fractional cent on which to make a megabuck. Sit through the glib introductory film, though, and the hectic scurrying and constantly moving hieroglyphs of the stock prices make more sense.

Along with the film, there's a small exhibition on the history of the Exchange – notably quiet on the more spectacular screw-ups. The most disastrous, the notorious "Black Tuesday" of 1929, is mentioned almost in passing, perhaps because it was so obviously caused by the greed and short-sightedness of the money men themselves. In those days, shares could be bought "on margin," which meant the buyer needed to pay only a small part of their total cost, borrowing the rest using the shares as security. This worked fine as long as the market kept rising – as share dividends came in to pay off the loans, investors' money bought more shares. But it was, as Alistair Cooke put it, "a mountain of credit on a molehill of actual money," and only a small scare was needed to start the avalanche. When the market investors had to find more cash to service their debts and make up for the fall in value of their stocks, they sold off their shares cheaply. A panicked chain reaction ensued, and on October 24, sixteen million shares were traded; five days later, the whole Exchange collapsed as $125 million was wiped off stock values. Fortunes disappeared overnight: millions lost their life savings; banks, businesses and industries shut their doors; and unemployment spiraled helplessly. The Great Depression began. It says much for the safety nets that surround the market's operations today that the equally tumultuous crash of October 1987 caused comparatively negligible reverberations.