white elephant

Legend has it that the once barren Queen Maya became pregnant with Siddhartha after dreaming of a white elephant. The animal has been regarded in high esteem every since. In fact, the number of white elephants a monarch owns reflects his own significance. The origin of the phrase “white elephant” lies in this very Thai tradition, that all white elephants must belong to the king. They are not used for work but are cared for at a huge expense. A useless investment in every sense of the word.

(Fun fact via my DK Eyewitness Travel Guide: Thailand)