Faced with the sheer diversity of the articles in this issue of Echogeo dedicated to urban structures and frameworks, ranging from the micro to the macro, we had to place the questions they address within a historical perspective, looking at the last half-century. The issues below are connected to the topics addressed in the papers, as well as outlining ideas that appear implicitly in the papers. What are likely to have been the main themes addressed in this issue forty or fifty years ago, d...