The discovery was made on Sunday on the Long Mynd.
Bomb disposal experts removed the shell and carried out a controlled explosion.
South Shropshire police said officers responded to a 999 call by a member of the public.
"They had stumbled across an early 20th century Anderson shell in Callow Hollow," a police spokesman said.
"A team from Explosive Ordnance Disposal removed it and conducted a controlled explosion."
Police prevented visitors from getting too close to the area while waiting for the shell to be removed.