OBDOISK, a name which is given to that part of Asiatic Russia which extends along the northern part of the course of the Obi to the Frozen Ocean. It is also the name of a small palisaded fort, the most northerly of any maintained by Russia, being garrisoned by an officer, with twenty-five Cossacks, who exercise a species of sovereign control over the scattered tribes of Ostiaks and Samoyedes.