In Scotland they’re called cairns. In the First Nations regions of northern Canada, the great swaths of ice that constitute much of the land where Inuit people have eked out a living for centuries, they are called Inukshuks.
This is a particularly lovely one, perched on the rock shore of Puget Sound. It won’t stay forever; nothing does. It’s up pretty high to be knocked over by a wave, and seems sturdy enough to withstand the wind. Most likely it will be upended, eventually, by human hand. People do that to the creations of others, for reasons that escape me.
They symbolism of the rock tower is twofold: to say that its creator was here, and to mark a pathway. Only the creator, in this case, knows the answer to “a pathway to what?”