Amsterdam started out as a fishing village on the marshlands and swamps off the Amstel River. In order to build on wet land the settlers set down foundations pinewood foundations sunk deep into the "mud". Homes were built tightly next to each other for support. Today we see some of them tilted forwards and others to the sides. Some are sinking on one side or the other and although they might create the allusion of a misshapen world, to me it's quite charming. Although, I can imagine that it is of great concern and a pain for those living in the area.