The parasol fungus (Macrolepiota procera) is a common, large and easy to identify fungus. It is well-known amongst foragers.
As the name suggests it has a broad, wide and often flat cap. The ring around the stem is prominent and hard to miss. The ring slides up and down the skinny stipe.
In natural navigation it is not a strong sign, but it can hint that you are near a woodland edge.
There are lots of clues we find in woodland that indicate that we are getting near the edge (eg. lichens, ivy, tree species). But this fungus is normally a sign that you are in open grassland, but that there is woodland nearby.