Thanks to six moon landings, hundreds of objects are still scattered across the surface of the moon: golf balls, boots, cameras, javelins, sculptures, photographs, and a golden olive branch. Because the moon doesn't have an atmosphere, most of these objects will remain preserved until something impacts that area of the moon.
Many of the objects left during the moon landings carry symbolic significance: a small aluminum sculpture honors the astronauts who died during the space race, both American and Soviet; a patch from the Apollo 1 mission that never launched because of disaster; a computer disk holding goodwill messages from 73 world leaders.
Not everything is symbolic, however. Scientific equipment was also left behind to continue monitoring the moon: lunar laser ranging retroreflector array and seismometers intended to measure seismic activity on the moon. The Apollo 11 astronauts' original space boots are also still there.
Last and perhaps least, out of necessity astronauts had use the moon for a landfill, disposing of hand wipes, towels, backpacks, as well as bags of urine, feces, and vomit.