Yes – Amsterdam was built on water. More substantively, the city was built on piles – large wooden stakes that are driven into the ground. The piles (or the stilts) are driven in the clay, pear and water until they reach the first layer of solid sand. They are literally a foundation for all Amsterdam's buildings.
In many cases, the wooden poles were of a lesser quality, not long enough or not thick enough. Safe to say, the builders did not give out a 300-year guarantee. The old age and quality of the wooden piles make the buildings in Amsterdam sink unevenly in the ground, making Amsterdam's houses appear skewed.