Description: Fort Nassau: Albany. First Dutch trading post and stockade 1614-1618. Built on Castle island East side of Hudson River South of present Rensselaer (Patroon's Island). Said to have been the first permanent building in New York. Washed out by a river flood. Fort Orange built on the riverbank in 1624. Island has merged with shore since then. The following was submitted by Cliff Lamere: The island was on the west side of the river. It was south of Albany, not Rensselaer. The "Patroon's Island" comment should be omitted. It is an island north of Rensselaer and has nothing to do with Fort Nassau. Mr. Lamere also submitted the following taken from: History of the State of New York: First Period, 1609-1664 by John Romeyn Brodhead (1853), pg 55. "Hendrick Christiaensen... constructed a trading house on "Castle Island," at the west side of the river, a little below the present city of Albany. This building, which was meant to combine the double purposes of a warehouse and a military defense for the resident Dutch traders, was thirty-six feet long, by twenty-six feet wide, inclosed by a stockade fifty-eight feet square, and the whole surrounded by a moat eighteen feet in width... The little post was immediately named "Fort Nassau." It was armed with two large guns, and eleven swivels or patereros, and garrisoned by ten or twelve men." "Said to have been the first permanent building in New York." I haven't heard that, but it might be true. New Amsterdam (NY city) also had people there in 1614. I wonder what the writer meant by permanent. Built about 1614, it was destroyed the following Spring by floods that were carrying blocks of ice. It lasted less than a year. That wasn't what I'd call permanent. The fort was rebuilt nearby onshore, but on the floodplain. In 1618 it was abandoned by the Dutch.