By the time it was inaugurated in 1665 (17 years after groundbreaking, which took place at the end of the “Eighty Year War” in 1648), “Het Stadthuis” designed by Jacob van Campen in cooperation with Pieter Post and Willem de Keyser to serve as Amsterdam’s City Hall, would prove to be the most oppulent and the largest such building, by far, in all of Europe. 

To keep the colossal building from sinking into the marshy and unstable, 24+ foot layer of water-laden peat underlying all of Amsterdam (a problem even today for any structure, large or small), the building was put on a foundation supported by 13,659 wooden poles, each about 32 feet long (to reach an underlying sandbar) and 20+ inches in diameter.  For a feel of what the pounding of 13,659 poles about 30 ft into the ground must have entailed, have a look at this 1709 drawing by Jan Luyken.  For an interior view of the palace (which, btw, didn’t become “The Palace” until 1805)

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