The fairly complicated routes to access the hidden diner are pictured on this page. First, climb a wooden scaffolding ramp from the west side of the junkyard east of the entrance to Diamond City, and enter South Fens Tower to the south. For the first route, climb the tower to the top, where a hole in the wall allows for a long "ledge jump" to a roof near the diner using a jet pack or Buffjet (taking advantage of its slow time effect). A second jump will then allow access to the roof with the diner.
For the second route, the diner can be reached without chems by making a sprinting jump to a ruined building to the west from the floor below the top floor of South Fens Tower. Once on the ruined building, climb the edge of the destroyed wall to the intact northeast corner of the roof. From the edge of the roof wall, another difficult sprinting jump to the north-northeast allows access to the roof near the diner. Taking a few steps to the east, crouching then jumping against the corner wall will launch you onto the roof's upper level. Finally, from the highest glassed peak of the roof, one more difficult sprinting jump to the north gives access to the roof with the diner.
- Mini nuke - In the diner, on the counter.
The hidden diner only appears in Fallout 4.