Above: Pictures from in and around Lake Superior Provincial Park in 2007 (examples of inuksuk, as well as my attempt at building one).
I first came across inuksuk and inunnguaq when I was little and my family went on a road trip in Canada. We saw small piles of rocks everywhere, some shaped like little people, and we were baffled until someone at a visitor center explained their purpose to us.
These cairns can be found near bodies of water, at trail heads, and near other places of interest. They help fellow travelers find interesting things and make navigation easier.
It is very exciting to be in a remote area, such as those found in the park, and discover a symbol or message someone else left for the next person who comes along. There is something mysterious and magical about that.
The word inuksuk means "something which acts for or performs the function of a person." The word comes from the morphemes inuk ("person") and -suk ("ersatz or substitute"). It is pronounced inutsuk in Nunavik and the southern part of Baffin Island (see Inuit language phonology and phonetics for the linguistic reasons). In many of the central Nunavut dialects, it has the etymologically related name inuksugaq (plural: inuksugait).
A structure similar to an inuksuk but meant to represent a human figure, called an inunnguaq ("imitation of a person", plural inunnguat), has become widely familiar to non-Inuit. However, it is not the most common type of inuksuk and is distinguished from inuksuit in general.