A secondary city is an urban hub that fills specific regional and local needs related to governance, economics, finance, education, trade, transportation. A secondary city is defined by population, area, function, and economic status, but also by their relationship to neighboring and distant cities and their socio-economic status. A secondary city may emerge from a cluster of smaller cities in a metropolitan region or may be the capital city of a province, state, or second-tier administrative unit within a country. Secondary cities are the fastest-growing urban areas in lower- and middle-income countries, experiencing unplanned growth and development. By 2030, there will be twice as many medium-size cities as there were in 1990, outnumbering the total number of megacities.[1] According to the World Bank, secondary cities make up almost 40% of the world cities population.[2] Many secondary cities in the Global South are expected to undergo massive expansions in the next few decades comparable to city growth in Europe and North America over the past two centuries.[3] These cities are unique environments that generally have limited data and information on infrastructure, land tenure, and planning.