Apollo 15 Hasselblad image from film magazine 93/P - lunar orbit view.
This is figure 3-36 of the Apollo 15 Preliminary Science Report (NASA SP-289, 1972), which has the following caption:

Eastern floor of Humboldt Crater. The mare-type material on the floor contains radial cracks and concentric rilles. A dark-halo area is visible at the lower left corner. Low hills of material that resemble the central peak protrude through the smooth crater floor. Bright-halo craters are also evident. The "doughnut" filling of the crater at the left margin is a rare feature.

This is shown as Figure 210 from Apollo Over the Moon (NASA SP-362, 1978), which has the following caption:

This picture of the interior of the crater Humboldt (approximately 200 km in diameter) was taken looking southward. The terraced crater wall lies in the background, and the central peaks are visible in the lower right hand portion of the picture. The crater floor is typical of those that exhibit both radial and concentric cracks, or fissures. The fissures and cracks appear to be related to the uplift of the crater floor subsequent to the formation of the crater. The deformation may be related to upwelling of portions of the crust in an attempt to reach isostatic equilibrium, or it may be coincident with intrusion of lavas below the crater floor. Small patches of dark mare material can be seen along the edge of the crater floor in the lower left and middle right hand portions of the picture.-J.W.H.