Nash also makes land art, of which the best known is "Wooden Boulder", begun in 1978. This work involves the journey of a large wooden sphere from a Welsh mountainside to the Atlantic Ocean. "Wooden Boulder" is a large wooden sphere carved by Nash in the North Wales landscape and left there to weather. Over the years, the boulder has slipped, rolled and sometime been pushed through the landscape following the course of streams and rivers until finally it was last seen in the estuary of the river Dwyryd. It was thought to have been washed out to sea but, after being missing for over five years, the boulder reappeared in June 2009. Indications are that it had been buried in sand in the estuary. The sculptor had no idea of its location, and enjoys the notion that wood which grew out of the land will finally return to it. The boulder was last seen in 2015.