In Southeast Asia, you would expect to find the most populous cities primarily along coastal regions and near wetlands and rain forests. Coastal areas provide access to trade routes, resources, and opportunities for fishing and tourism, which attract populations. Additionally, wetlands and regions near rain forests often have fertile land and abundant water resources, which are conducive to agriculture and settlements.
In contrast, cities located in interior highlands or deserts and plateaus are less common due to harsher living conditions, limited agricultural potential, and lower accessibility to trade routes.