>like a suprisingly large proportion of capital cities Not a massive surprise - Cities are enduring hubs for commerce, and so usually rise around strong transp

>like a suprisingly large proportion of capital cities Not a massive surprise - Cities are enduring hubs for commerce, and so usually rise around strong transport infrastructure, which going back far enough meant waterways. Extensive development is facilitated with the presence of large areas of flat land. Put those two together and you're looking for flatland surrounding major waterways: Swamps and marshes.