It is a rare city, town or village that rises from a flat plain. Land goes up and down. People, however, prefer things to be level. Slanted floors are annoying, especially for the bookcases and furniture. Slanted buildings tend to fall down. In the good old days you’d just build your structure however you felt like it, and the roads, sewage, and so on would accommodate you when they were installed, maybe centuries later. This first picture shows me in front of a stone hut in which level floors and square walls were a sophistication yet undreamed of.
However, once you advance to agglomerations of buildings, the zoning people begin to get picky. The city would like its roads to be level. Stepped to accommodate the grade was okay when the traffic was horses and donkeys, but it’s no good for automobiles. And therefore it’s the buildings that have to be slanty, so that the road in front can go smoothly down while the floor stays level. The main library in town shows the kind of trick architects resort to. The road goes downhill, and there are more steps added as the land drops away. Railings keep people from tripping over steps that suddenly are not there.
This is another view of the library’s frontage. A balustrade steps down as the land slopes, and they inserted benches to make it look graceful and friendly. A bug becomes a feature! If you walk around the library, which takes up the entire city block, you would see that the most downhill side is a full story higher than the opposite, most uphill side. They actually installed a slightly sunken garden there, so that there could be windows there. The building is dead level. Clever architecture hides all the adjustments.