Cross reference
Mark 5:20
20 He went his way, and began to proclaim in Decapolis how Jesus had done great things for him, and everyone marveled.
Matthew 4:25
25 Great multitudes from Galilee, Decapolis, Jerusalem, Judea and from beyond the Jordan followed him.
Mark 7:31
31 Again he departed from the borders of Tyre and Sidon, and came to the sea of Galilee, through the midst of the region of Decapolis.