Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Independence Hall | Building | 9 | Philadelphia | 39 56 55 N | 075 09 01 W |
| Indian Steps Museum | Building | 62 | York | 39 51 49 N | 076 22 36 W |
| International Coin Museum | Building | 8 | Philadelphia | 39 57 02 N | 075 08 51 W |
| Ironore P O (historical) | Building | 164 | York | 39 50 23 N | 076 54 38 W |
| Ivy Mills Station | Building | 58 | Delaware | 39 53 06 N | 075 29 09 W |
| Ivy Ridge Station | Building | 28 | Philadelphia | 40 02 00 N | 075 14 05 W |
| Jacks Run Docks Station | Building | 220 | Allegheny | 40 28 58 N | 080 03 00 W |
| Jacksonian Apartments | Building | 288 | Allegheny | 40 30 02 N | 080 03 27 W |
| Japanese House | Building | 30 | Philadelphia | 39 58 53 N | 075 12 46 W |
| Jefferson County Gas Company Pumping Station | Building | 524 | Jefferson | 41 18 24 N | 079 05 11 W |
| Jenkintown Station | Building | 81 | Montgomery | 40 04 36 N | 075 08 17 W |
| Jermyn Number Five Colliery Breaker (historical) | Building | 253 | Lackawanna | 41 27 59 N | 075 37 21 W |
| Jermyn Number Four Breaker | Building | 232 | Lackawanna | 41 27 43 N | 075 37 13 W |
| Jermyn Shaft Breaker | Building | 297 | Lackawanna | 41 31 41 N | 075 32 31 W |
| John Harris Mansion | Building | 98 | Dauphin | 40 15 18 N | 076 52 38 W |
| Joseph Priestley House | Building | 139 | Northumberland | 40 53 25 N | 076 47 24 W |
| Junction Whitehall Station | Building | 275 | Allegheny | 40 25 29 N | 079 57 01 W |
| Kelly Township Office | Building | 154 | Union | 40 59 42 N | 076 52 55 W |
| Keplers Mill Station | Building | 76 | Northampton | 40 41 58 N | 075 14 30 W |
| Keystone Colliery | Building | 267 | Luzerne | 41 16 42 N | 075 47 49 W |
| Keystone Job Corp Center | Building | 346 | Luzerne | 41 00 20 N | 075 59 09 W |
| Kimberton Fish and Game Association | Building | 104 | Chester | 40 09 15 N | 075 39 19 W |
| King Museum | Building | 296 | Allegheny | 40 28 45 N | 079 55 29 W |
| Knowlton Station | Building | 24 | Delaware | 39 52 36 N | 075 24 59 W |
| Laflin Station | Building | 221 | Luzerne | 41 17 23 N | 075 48 26 W |
| Lahaska Station | Building | 77 | Bucks | 40 20 16 N | 075 00 50 W |
| Lansdowne Station | Building | 36 | Delaware | 39 56 14 N | 075 16 14 W |
| Lansdowne Station (historical) | Building | 12 | Delaware | 39 55 56 N | 075 16 49 W |
| Large Station | Building | 247 | Allegheny | 40 17 28 N | 079 55 19 W |
| Lauria Ann West Community Center | Building | 294 | Allegheny | 40 30 49 N | 079 51 24 W |
| Lauria Ann West Library | Building | 294 | Allegheny | 40 30 49 N | 079 51 24 W |
| Lawn Crest Recreation Center | Building | 43 | Philadelphia | 40 02 46 N | 075 06 01 W |
| Lawndale Station | Building | 43 | Montgomery | 40 03 06 N | 075 06 05 W |
| Leader Nursing Rehabilation Center | Building | 68 | Montgomery | 40 15 24 N | 075 38 17 W |
| Lebanon County Home | Building | 149 | Lebanon | 40 20 29 N | 076 23 26 W |
| Lemoyne House | Building | 334 | Washington | 40 10 03 N | 080 14 38 W |
| Leonard Post Office (historical) | Building | 164 | Chester | 39 53 09 N | 075 46 26 W |
| Lewis Run Junction Station | Building | 232 | Allegheny | 40 25 34 N | 080 05 11 W |
| Liberty Bell Pavilion | Building | 10 | Philadelphia | 39 57 02 N | 075 09 02 W |
| Liberty Fire Company Number One | Building | 96 | Dauphin | 40 11 40 N | 076 43 15 W |
| Library Hall | Building | 8 | Philadelphia | 39 56 51 N | 075 08 58 W |
| Lickdale Community Fire Company | Building | 133 | Lebanon | 40 27 10 N | 076 30 44 W |
| Lighthouse Field | Building | 32 | Philadelphia | 40 00 31 N | 075 07 28 W |
| Lillian Home Heart House | Building | 335 | Butler | 40 40 43 N | 079 59 44 W |
| Lincoln Grange Hall | Building | 302 | Huntingdon | 40 21 19 N | 078 11 42 W |
| Lingohocken Fire Company-Station 95 | Building | 85 | Bucks | 40 17 31 N | 075 03 32 W |
| Little League Baseball Headquarters and Museum | Building | 179 | Lycoming | 41 13 50 N | 076 58 50 W |
| Lockport Station | Building | 325 | Westmoreland | 40 23 30 N | 079 07 23 W |
| Logan Station | Building | 37 | Philadelphia | 40 01 45 N | 075 08 49 W |
| Londonderry Fire Company Number 1 | Building | 165 | Dauphin | 40 11 25 N | 076 41 25 W |
| Londonderry Post Office (historical) | Building | 193 | Chester | 39 51 51 N | 075 53 06 W |
| Londonderry Township Municipal Building | Building | 142 | Dauphin | 40 10 53 N | 076 41 45 W |
| Longview Station | Building | 372 | Allegheny | 40 20 25 N | 080 00 58 W |
| Lovett Memorial Library | Building | 107 | Philadelphia | 40 03 25 N | 075 11 14 W |
| Lucas Station | Building | 267 | Allegheny | 40 25 09 N | 079 57 48 W |
| Lundys Lane Post Office (historical) | Building | 287 | Erie | 41 53 33 N | 080 20 20 W |
| Lutheran Home for the Aged | Building | 129 | Bucks | 40 19 45 N | 075 19 45 W |
| Lutheran Orphans Home | Building | 101 | Philadelphia | 40 03 19 N | 075 11 19 W |
| Lysock-View County Home | Building | 186 | Lycoming | 41 16 33 N | 076 55 25 W |
| M E Home for the Aged | Building | 75 | Philadelphia | 39 59 45 N | 075 12 59 W |
| M E Orphanage | Building | 71 | Philadelphia | 39 59 53 N | 075 12 53 W |
| Maccabees Home | Building | 130 | Chester | 39 51 23 N | 075 48 56 W |
| Malstead Breaker (historical) | Building | 182 | Luzerne | 41 21 07 N | 075 45 26 W |
| Malvern Institute | Building | 158 | Chester | 40 01 40 N | 075 32 40 W |
| Man Full of Troubles Tavern | Building | 6 | Philadelphia | 39 56 40 N | 075 08 42 W |
| Manayunk Station | Building | 19 | Philadelphia | 40 01 36 N | 075 13 29 W |
| Mann Music Center | Building | 45 | Philadelphia | 39 58 57 N | 075 13 19 W |
| Manor Meeting House | Building | 104 | Lancaster | 39 59 03 N | 076 23 32 W |
| Maple Grove Arena | Building | 105 | Lancaster | 40 02 07 N | 076 20 27 W |
| Marine Corps Memorial Museum | Building | 7 | Philadelphia | 39 56 53 N | 075 08 50 W |
| Maritime Museum | Building | 7 | Philadelphia | 39 56 56 N | 075 08 50 W |
| Marshwood Colliery | Building | 455 | Lackawanna | 41 26 04 N | 075 33 56 W |
| Martins Creek Station (historical) | Building | 115 | Northampton | 40 49 45 N | 075 11 59 W |
| Martinsburg Sportsmens Lodge | Building | 371 | Blair | 40 22 42 N | 078 14 58 W |
| Maurglen Post Office (historical) | Building | 216 | Lycoming | 41 18 49 N | 076 39 12 W |
| McKees Rocks Station | Building | 224 | Allegheny | 40 28 37 N | 080 03 42 W |
| Meadowbrook Station | Building | 40 | Montgomery | 40 06 42 N | 075 05 35 W |
| Mellon Memorial Library | Building | 283 | Allegheny | 40 25 56 N | 079 53 06 W |
| Memorial Auditorium | Building | 355 | Cambria | 40 19 22 N | 078 55 21 W |
| Memorial Hall | Building | 37 | Philadelphia | 39 58 45 N | 075 12 35 W |
| Mennonite Home | Building | 92 | Lancaster | 40 03 53 N | 076 20 43 W |
| Mercer Museum | Building | 119 | Bucks | 40 18 29 N | 075 07 35 W |
| Merchants Exchange | Building | 6 | Philadelphia | 39 56 49 N | 075 08 47 W |
| Merkle Station | Building | 116 | Lehigh | 40 31 55 N | 075 36 06 W |
| Methodist Home for Children | Building | 134 | Cumberland | 40 13 02 N | 076 58 11 W |
| Metropolitan Edison Substation | Building | 142 | Lebanon | 40 26 40 N | 076 30 39 W |
| Michener Art Museum | Building | 121 | Bucks | 40 18 30 N | 075 07 35 W |
| Michters Distillery | Building | 153 | Lebanon | 40 16 38 N | 076 19 05 W |
| Middletown Public Library | Building | 98 | Dauphin | 40 11 44 N | 076 43 58 W |
| Midtown Station | Building | 232 | Allegheny | 40 26 25 N | 079 59 46 W |
| Midway Volunteer Fire Company - Station 13 | Building | 119 | Bucks | 40 21 29 N | 075 05 05 W |
| Midway Volunteer Fire Company- Station 5 | Building | 100 | Bucks | 40 20 47 N | 075 02 02 W |
| Mifflin Mine Station | Building | 270 | Allegheny | 40 22 23 N | 079 52 22 W |
| Miguon Station | Building | 19 | Montgomery | 40 03 33 N | 075 15 59 W |
| Millvale Station | Building | 240 | Allegheny | 40 28 46 N | 079 58 01 W |
| Monaghan P O (historical) | Building | 225 | York | 40 08 09 N | 076 57 49 W |
| Monongahela Junction Station | Building | 233 | Allegheny | 40 23 08 N | 079 51 19 W |
| Monroe County Correctional Facility | Building | 153 | Monroe | 40 57 00 N | 075 17 21 W |
| Montgomery County Prison Farm | Building | 135 | Montgomery | 40 09 36 N | 075 25 19 W |
| Montgomery Hill Detention Home | Building | 57 | Montgomery | 40 07 47 N | 075 23 29 W |
| Moosic Powder Works (historical) | Building | 199 | Lackawanna | 41 21 08 N | 075 43 41 W |
| Moosic Power Company Mills | Building | 286 | Lackawanna | 41 31 12 N | 075 32 47 W |
| Moravian Seminary for Girls | Building | 129 | Northampton | 40 40 44 N | 075 18 51 W |
| Morea | Building | 453 | Schuylkill | 40 47 21 N | 076 10 14 W |
| Morgan Log House | Building | 86 | Montgomery | 40 14 42 N | 075 18 45 W |
| Morgans Station | Building | 6 | Delaware | 39 52 07 N | 075 24 29 W |
| Morss Tannery (historical) | Building | 345 | Lackawanna | 41 35 35 N | 075 29 05 W |
| Morton Station | Building | 40 | Delaware | 39 54 30 N | 075 19 38 W |
| Mount Alverno Station | Building | 19 | Delaware | 39 52 54 N | 075 25 37 W |
| Mount Jessup Colliery | Building | 286 | Lackawanna | 41 28 32 N | 075 33 29 W |