Monumental
WordNet
adjective
(1) Imposing in size or bulk or solidity
"Massive oak doors"
"Moore's massive sculptures"
"The monolithic proportions of Stalinist architecture"
"A monumental scale"
(2) Of outstanding significance
"Einstein's monumental contributions to physics"
(3) Relating or belonging to or serving as a monument
"The use of the arch in monumental architecture"
"Monumental sculptures"