Pennsylvania - Criteria: A (event)
| Knipe-Johnson Farm |
| Knipe-Moore-Rupp Farm |
| Knisley, Dr., Covered Bridge |
| Knoebel, Lawrence L., Covered Bridge |
| Knorr-Bare Farm |
| Knurr Log House |
| Kochendefer Covered Bridge |
| Koehler, Jackson, Eagle Brewery |
| Kooser State Park Family Cabin District |
| Kramer Covered Bridge No. 113 |
| Krauskap, Henry, House, and Store |
| Kreider Shoe Manufacturing Company |
| Kreiderville Covered Bridge |
| Kreigbaum Covered Bridge |
| Krepps Covered Bridge |
| Kulp, Isaac, Farm |
| Kuster Mill |
| Kutz Mill |
| La Blanche Apartments |
| Lacawac |
| Lackawanna Avenue Commercial Historic District |
| Lackawanna County Courthouse and John Mitchell Monument |
| Lackawanna Iron and Coal Company Furnace |
| Lady Washington Inn |
| Lafayette's Quarters |
| Lairdsville Covered Bridge |
| Lake City School |
| Lancaster Armory |
| Lancaster City Historic District |
| Lancaster County Courthouse |
| Lancaster County House of Employment |
| Lancaster Crematorium |
| Lancaster Historic District |
| Lancaster Trust Company |
| Lancaster Watch Company |
| Landis Homestead |
| Landis Mill Covered Bridge |
| Landis Shoe Company Building |
| Landis Valley Museum |
| Langhorne Historic District |
| Langley High School |
| Lansdale Silk Hosiery Company-Interstate Hosiery Mills, Inc. |
| Lansford Historic District |
| Larkin-Belber Building |
| Larkin Covered Bridge |
| Latrobe Armory |
| Laurel Hill Furnace |
| Laurel Hill RDA |
| Lawrence County Courthouse |
| Lawrence Public School |
| Lazaretto, The |
| Lea, Henry C., School of Practice |
| Leaman Place Covered Bridge |
| Leap-the-Dips |
| Leas, Benjamin B., House |
| Leatherman Covered Bridge |
| Leesport Lock House |
| Lee Tire and Rubber Company |
| Lehigh Canal |
| Lehigh Valley Railroad Headquarters Building |
| Lehigh Valley Silk Mills |
| Lehman's, Port Royal Covered Bridge |
| Lehner Grain-and-Cider Mill and House |
| Leiby, Jacob, Farm |
| Leidy, Dr. Joseph, House |
| Lemington Elementary School |
| Lemont Historic District |
| LeMoyne Crematory |
| LeMoyne, F. Julius, House |
| Lerch Tavern |
| Letsche Elementary School |
| Levan Farm |
| Lewisburg Armory |
| Lewisburg Historic District |
| Lewistown Armory |
| Liberty Bridge |
| Liberty Fire Company No. 5 |
| Liberty Hall |
| Lightfoot Mill |
| Ligonier Armory |
| Ligonier Historic District |
| Lilly Bridge |
| Lime Valley Covered Bridge |
| Lincoln, Mordecai, House |
| Linden Avenue School |
| Linden House |
| Linn Run State Park Family Cabin District |
| Lionville Historic District |
| Lippincott Covered Bridge |
| Lititz Moravian Historic District |
| Lits Department Store |
| Little Buffalo Historic District |
| Little Gap Covered Bridge |
| Little Jerusalem AME Church |
| Little, Moses, Tavern |
| Livingood House-Stryker Hospital |
| Lobb's Cemetery and Yohogania County Courthouse Site |
| Locomotive No. 6755 |
| Logan Demonstration School |
| Logan Mills Covered Bridge |
Data from United States Park Service and Wikidata
