北城以北深海未眠南城以南浅夏未过
[bĕi chéng yĭ bĕi shēn hăi wèi mián nán chéng yĭ nán qiăn xià wèi guò]
This name suggests contrasting themes between the northern and southern cities. The deep sea hasn't slept in the North while a light summer has yet to pass in the South, expressing an emotional or temporal disconnection.