Old Petaluma Opera House | |
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| Location | 147-149 Kentucky St., Petaluma, California |
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| Coordinates | 38°14′5.8″N 122°38′31.5″W / 38.234944°N 122.642083°W |
| Area | 0.1 acres (0.040 ha) |
| Built | 1870 |
| Architect | Brainerd Jones |
| Architectural style | Beaux Arts, Stick/Eastlake |
| NRHP reference No. | 78000801[1] |
| Added to NRHP | December 22, 1978 |
The Old Petaluma Opera House (also known as the Maclay Building) is a historic building located in downtown Petaluma, California.