Someone told me that one of San Francisco's oldest firehouses was located at 451 Pacific Avenue, but all I could find was a pair of ficus trees. Must have been misinformed.

Vintage San Francisco Firehouses

Engine Company No. 1, 451 Pacific Avenue
Engine Company No. 2, 460 Bush Street
Engine Company No. 7, 3160 16th Street
Engine Company No. 8, 1648 Pacific Avenue
Engine Company No. 9 and Fire Boat House, Pier 22½, Embarcadero at Harrison

Engine Company No. 13, 1458 Valencia Street
Engine Company No. 14, 1051 McAllister Street
Engine Company No. 16, 909 Tennessee Street
Engine Company No. 21, 1152 Oak Street
Engine Company No. 22, 1348 10th Avenue

Engine Company No. 23, 3022 Washington Street
Engine Company No. 24, 100 Hoffman Avenue
Engine Company No. 25, 3305 Third Street
Engine Company No. 27, 52 Waller Street
Engine Company No. 30, 1757 Waller Street

Engine Company No. 31, 1088 Green Street
Engine Company No. 33, 117 Broad Street
Engine Company No. 37, 2501 25th Street
Engine Company No. 40, 1249 Clayton Street
Engine Company No. 43, 724 Brazil Avenue

Engine Company No. 44, 3816 22nd Street
Engine Company No. 47, 1298 Girard Street
Engine Company No. 48, 798 Wisconsin Street
Dennis T Sullivan Memorial Fire Chief's Home
Pumping Station No. 2
Underwriter's Fire Patrol, 147 Natoma Street

GuardiansofTheCity.org is the definitive Web guide to San Francisco firehouses, both vintage and modern.