Shea was near the Valley Green Inn, on Forbidden Drive, in the Wissahickon Valley Park, about 1:15 p.m. Monday when he was hit from behind.
"I felt a real something to the head, a real blow to the head from behind," he said. "It knocked me to the ground; that was the biggie."
Shea said the four assailants continued to beat him for minutes while he was on the ground. He said they were black, appeared to be between 16 and 20, and three of them were wearing La Salle sweatshirts.
Police and Shea said that at least one of the attackers used a rock to hit him, causing deep cuts above his eyes. They all kicked and punched him while he was on the ground, conscious the entire time.
"There was only one I really saw well because he came back to kick me," Shea said. "The others spent a great deal of the time laughing."
The real "stunner" to Shea is that they left without trying to take his wallet, keys or cellphone.
"I think it was just to get the old geezer," Shea said. "They were some bad kids with rancid souls."
He tried to walk back to the Valley Green Inn alone, dripping with blood, but a bicyclist came to his aid.
Shea spent four hours at Chestnut Hill Hospital, getting stitches in his face - from his eyelid to his cheek - and treatment for two large scrapes on his leg and elbow. Shea also said two bones in his nose were broken.
The attackers have not yet been caught, police said yesterday. Despite that, Shea said he plans to be back out walking on Forbidden Drive next week.
"I hope to make myself do it," he said. "It's been a wonderful thing for me at my age."