The existence of these city maps has proven to be very useful in the archaeology of New York City. For instance, the Castello map aided the excavation of the Stadthuys (City Hall) of New Amsterdam in determining the exact location of the building. The maps enable a precise reconstruction of the town. Fort Amsterdam was located at the most southern tip of the island of Manhattan, which today is surrounded by Bowling Green. The Battery is a reference to its batteries or cannons. Broadway was the main street that led out of town north towards Harlem. The town was surrounded to the north by a wall leading from the eastern to the western shore. The course of this city wall is today Wall Street. A canal led from the harbor inland and was filled in 1676, which today is Broad Street. The layout of the streets was winding, as in a European city. Only starting from Wall Street going toward uptown did the typical grid become enforced long after the town ceased to be Dutch. Most of the Financial District overlaps New Amsterdam and has retained the original street layout. The 1625 date of the founding of New Amsterdam is now commemorated in the official Seal of New York City. (Formerly, the year on the seal was 1664, the year of the provisional Articles of Transfer, assuring New Netherlanders that they "shall keep and enjoy the liberty of their consciences in religion", negotiated with the English by Peter Stuyvesant and his council.) Sometimes considered a dysfunctional trading post by the English who later acquired it from the Dutch, Russell Shorto, author of "The Island at the Center of the World", suggests that the city left its cultural marks on later New York and, by extension, the United States as a whole. Major recent historical research has been based on a set of documents that have survived from that period, untranslated. They are the administrative records of the colony, unreadable by most scholars. Since the 1970s, a professor named Charles Gehring has made it his life's work to translate this first-hand history of the Colony of New Netherland. The scholarly conclusion has largely been that the settlement of New Amsterdam is much more like current New York than previously thought. Cultural diversity and a mindset that resembles the American Dream were already present in the first few years of this colony. Writers like Russell Shorto argue that the large influence of New Amsterdam on the American psyche has largely been overlooked in the classic telling of American beginnings, because of animosity between the English victors and the conquered Dutch.