Denver. Buildings . Heights of Mr 19, 1978 No. 6 ` First of Denver Plaza ... .. ...... 32 stories 472,000 sq. ft. 1974 No. 7 Colorado Natl. Bldg ...... ..... 26 stories 417,800 sq: ft. 1915 No. 8 Security Life Bldg. . .. . ... . 31 stories 397.000 sq. ft. 1994 No. 9 Cadillac-Fairview ......:..... . 24 stories 388,000 sq. ft. 1978 . No. 10 United Bank Center ............. 21 stories 385,000 sq. ft. 1955 No. 11 Colorado State Bank ... ......... 27 stories 380;000 sq. ft. 1971 No. 12 Lincoln Center Bldg ..... ....... 31 stories 342,600 sq. ft. 1972 No. 13 Great-West Tower (Phase 1) .... 27 stories 325,000 sq. ft. 1979 No. 14 First National Bank ..... ....... 28 stories 320,000 sq. ft. 1958 No. 15 Lincoln Tower Bldg. ....:....... 15 stories 283,.500 sq. ft. 1964 Pos': Mr 19, 1.978 p. IE 0