渤澥桑田 [－－－－]

Jyutping but6 haai5 song1 tin4
Pinyin bó xiè sāng tián

Definitions (CC-CEDICT)
  1. lit. blue seas where once was mulberry fields (idiom, from 史記|史记[Shi3 ji4], Record of the Grand Historian); time brings great changes
  2. life's vicissitudes