Here is text copied from the Hwaseong Fortress brochure:
“Hwaseong Fortress in Suwon City was begun by King Jeongjo, 1776-1800, the 22nd king of the Joseon Dynasty, in honor of his deceased father, Sado Deja.
Sado Seja had been designated as Crown Prince, but became the victim of a court conspiracy and was unjustly condemned by his father…