Subterranian City Planning
A lot of fantasy has entire large populations living underground. Assuming basic things that every city needs (rivers for water and sanitation) and appropriately fantastic geology (enough massive cave systems to be populated by huge numbers of these peoples) how do you think such a city would look on the small scale? Alleys and courtyards seem out as they appear under normal conditions when a back lot gets boxed in, and the extra effort of moving dirt for many buildings means that more planning in general will probably go into these cities and they seem more likely to be compact to me. What other details should and would be different? I'm interested in people thoughts on this.