Pennsylvania - Area of significance: Engineering
| Holme Avenue Bridge |
| Homestead High-Level Bridge |
| Horseshoe Curve |
| Horse Valley Bridge |
| Horsham-Montgomery Bridge |
| Howard Tunnel, Northern Central Railway |
| Ironstone Bridge |
| Jacksons Mill Covered Bridge |
| Jacobsburg Historic District |
| Jerome Street Bridge |
| John's Burnt Mill Bridge |
| Johnson Covered Bridge No. 28 |
| Johnson, Nicholas, Mill |
| Johnstown Inclined Railway |
| Josiah Hess Covered Bridge No. 122 |
| Jud Christie Covered Bridge No. 95 |
| Kauffman Mill |
| Kaufman's Distillery Covered Bridge |
| Keefer Covered Bridge No. 7 |
| Keller's Covered Bridge |
| Kennedy Bridge |
| King's Bridge |
| Kingston Armory |
| Kintersburg Covered Bridge |
| Kise Mill Bridge |
| Knabb-Bieber Mill |
| Knecht's Mill Covered Bridge |
| Knisley, Dr., Covered Bridge |
| Kramer Covered Bridge No. 113 |
| Kreiderville Covered Bridge |
| Kutz's Mill Bridge |
| Lackawanna Iron and Coal Company Furnace |
| Lancaster City Historic District |
| Landis Mill Covered Bridge |
| Larkin Covered Bridge |
| Lawrenceville Historic District |
| Layton Bridge |
| Leaman Place Covered Bridge |
| Leap-the-Dips |
| Lehigh Canal |
| Lehigh Canal; Allentown to Hopeville Section |
| Lehigh Canal: Eastern Section Glendon and Abbott Street Industrial Sites |
| Lehigh Water Gap Chain Bridge Toll House and East Bridge Abutment |
| Lenape Bridge |
| Liberty Bridge |
| Lilly Bridge |
| Lime Valley Covered Bridge |
| Lindbergh Viaduct |
| Little Gap Covered Bridge |
| Lloyd and Henry Warehouse |
| Logan Mills Covered Bridge |
| Loller Academy |
| Loux Covered Bridge |
| Lower Humbert Bridge |
| Manasses Guth Covered Bridge |
| Marion Bridge |
| Market Street Bridge |
| Market Street Bridge |
| Marshall's Bridge |
| Mauch Chunk and Summit Hill Switchback Railroad |
| McClay's Twin Bridge (East) |
| McClay's Twin Bridge (West) |
| McConnell's Mill Covered Bridge |
| McCormick, John B., House |
| McKees Rocks Bridge |
| Mercer Museum |
| Mercer's Mill Covered Bridge |
| Meyers, Albertus L., Bridge |
| Millanville-Skinners Falls Bridge |
| Minersville Coke Ovens |
| Mount Vernon Furnace |
| Muddy Creek Bridge, Maryland and Pennsylvania Railroad |
| Neff's Mill Covered Bridge |
| Neuweiler Brewery |
| New Baltimore Bridge |
| Newtown Creek Bridge |
| Ninth Street Bridge |
| Noon, Philip, House |
| Northampton County Bridge No. 15 |
| North Charlotte Street Historic District |
| Old Columbia-Wrightsville Bridge |
| Old Waterworks |
| Osterburg Covered Bridge |
| Packard Motor Corporation Building |
| Packsaddle Bridge |
| Parr's Mill Covered Bridge No. 10 |
| Patterson Covered Bridge No. 112 |
| Pennsylvania Canal Guard Lock and Feeder Dam, Raystown Branch |
| Pennsylvania Main Line Canal, Juniata Division, Canal Section |
| Pennsylvania Railroad Bridge |
| Pennsylvania Railroad Bridge over Shavers Creek |
| Pennsylvania Railroad District |
| Pennsylvania Railroad Old Bridge over Standing Stone Creek |
| Perkiomen Bridge |
| Philadelphia Naval Shipyard Historic District |
| Philadelphia Racquet Club |
| Philadelphia Savings Fund Society Building |
| Philadelphia, Wilmington and Baltimore Railroad Freight Shed |
| Pine Grove Covered Bridge |
| Pinetown Covered Bridge |
Data from United States Park Service and Wikidata
