This was the old location of Chex TV and Radio in Peterborough, which from my research dates back to 1955. Chex was the first television company in Peterborough and still services the area today. There was a fairly large television studio and radio broadcasting centre here including two large satellite dishes (which are still there) and a massive broadcasting tower (replaced by a more modern one sometime ~1988). The current tower is over a kilometer high and services all of Peterborough with cellphone coverage and television. Sometime in the late 80's a storm knocked down the tower and Chex decided to move from their (getting cramped) location to a new location in Peterborough proper while the new tower was put in place.
The foundation, parking lot, basement area, lot lighting, satellite dishes, tower foundations and some walls still remain today. It's a really cool spot and one can see across most of Peterborough from it. There are two active cell towers on the hill near the remains of the television studio, one small and one massive. The large one has a building next to it that is for servicing it but it is rarely used and you are unlikely to encounter anyone up here.
Definitely worth a visit!