However, Ukyo, otherwise known as the 'Choan' side, soon fell out of use due to its many wetland areas, leaving Sakyo, or 'Rakuyo' as it was also known, as the only urban area.
ところが、右京すなわち「長安」側は湿地帯が多かったことなどから程なく廃れ、市街地は実質的に左京すなわち「洛陽」だけとなった。