Born in 1941, Fernando Varanda is an architect, urban designer and university professor in Lisbon. He spent several years in Yemen, first working from 1973 to 1975 for the United Nations Developed Program and, later, under the auspices of the Calouste Gulbenkian Foundation in Lisbon, to undertake the study that resulted in this book. He is the author of two other books that were structured along the same method, on the interaction between natural and built environment in Portugal; and of numerous articles based on similar surveys made in different countries.