Some of these courtyard houses were predictably just demolished, which left an empty site for denser, taller architecture to be built up. Those in those open courtyards I was talking about became packed with these new buildings. And residents just sort of negotiated this mishmash of remaining voids so that everybody could have at least some narrow path into and out of the complex to get to their house. The Houtong alleys were running alongside these big residential blocks. They basically had to make more Houtongs to reach everything inside.