 About 250 Pictish stones survive and have been assigned by scholars to three classes . Class I stones are those thought to date to the period up to the seventh century and are the most numerous group . The stones are largely <unk> and include <unk> symbols of animals such as fish and the Pictish beast , everyday objects such as mirrors , <unk> and tuning forks and abstract symbols defined by names including V @-@ rod , double disc and Z @-@ rod . They are found between from the Firth of Forth to Shetland . The greatest concentrations are in Sutherland , around modern Inverness and Aberdeen . Good examples include the <unk> ( Sutherland ) and <unk> stones ( Angus ) . 
