Adjectives

(s)baronial, imposing, noble, statelyimpressive in size, manner, or appearance“a baronial mansion”, “an imposing residence”, “a noble tree”, “severe-looking policemen sat astride noble horses”, “stately columns”
(s)stately, statuesqueof size and dignity suggestive of a statue
(s)courtly, formal, statelyrefined or imposing in manner or appearance; befitting a royal court“a courtly gentleman”