Buzz Aldrin's bootprint on the Moon, AS11-40-5877 (21472308758)

Apollo 11 Hasselblad image from film magazine 40/S - EVA
The NASA Special Publication 246, Lunar Photographs from Apollos 8, 10, and 11 (1971) has the following caption for this photo:

This overhead view shows a detailed section of the lunar surface and the amount of compaction caused by the weight of a man.

This photo was used in Figure 1-27 in the Apollo 11 Preliminary Science Report (NASA SP-214), 1969, which has the following caption:

The astronaut photographed his own footprint to permit later study of the lunar surface bearing strength. The thin, crusty appearance of the surface was similar to that discovered during the Surveyor soil mechanics experiments. (NASA AS11-40-5877)

This photo was used again in Figure 3-12 in the Apollo 11 Preliminary Science Report, which has the following caption:

Hasselblad photograph AS11-40-5877 showing an astronaut's bootprint in the lunar surface.

This photo was used again in Figure 4-24 in the Apollo 11 Preliminary Science Report, which has the following caption:

Same surface as shown in figure 4-23 after having been stepped on by an astronaut. Note the bulged and cracked region in front and to the sides of the footprint. (NASA AS11-40-5877)