There are no rocks suitable for climbing in Tri-City (in Polish: Trójmiasto, i.e. Gdańsk, Gdynia and Sopot). The nearest climbing area lies at least several hundred kilometers far from here (northwards Sweden, southwards Jura) and local climbers climb only artificial walls. Since the end of the 60's they have climbed primarily some old railway bridges left after dismantling a railway after World War II, and later on other abandoned buildings.
Murki is a Polish climbers' name for objects built originally not for the sake of climbing but ultimately used precisely in this purpose. Because the routes once prepared on murki are never changed — as opposed to most of other artificial walls — climbing here resembles a little natural rock climbing.