Tremendous in size, volume, or degree: Gigantic, Colossal. (Merriam – Webster)
Enormous. (Oxford Dictionaries)
Very large: (Cambridge Dictionary)
Gargantuan God of War statue in China offers quite a sight.
12 Old Words for the Huge, Mammoth, and Gargantuan.
Unmeet, Hideous, Hugy and Hugeous, Brobdingnag, Honking, Masterous, Dimensionless, Immensive and Gigantine, Pythonic, Fattening Hod.