A "castle of dragon" is a term that cannot be easily converted into synonyms due to its specificity. However, some related terms include "dragon citadel," "dragon fortress," "dragon stronghold," and "dragon keep." These synonyms share similar connotations to a "castle of dragon," referring to a powerful and protected residence of a dragon. In fantasy literature and gaming, the term may also be substituted with "lair of the dragon." While these terms may not have the same rhythm and resonance as a "castle of dragon," they serve as alternative descriptors for the same concept in various creative contexts.