Metal fencing has been placed around Hartshead Pike in Ashton because of safety concerns.
The Grade-II listed tower, which dates back to the 18th century, is one of the borough's best-known landmarks.
Fencing and a health and safety notice was put around the historic site by the council.
A Tameside Council spokesperson told the Reporter on Monday: “Due to the age and location of Hartshead Pike, we are in the process of carrying out structural surveys to establish the level of repair work that we will need to undertake.
"We have put up some temporary fencing around the Pike as a precaution and would just ask that people don’t go beyond this fencing and to please bear with us while we carry out the initial works."
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