Hartshead Pike has been fenced off because of safety concerns.
The Grade-II listed structure dates back to the 18th century and is one of Tameside's best-known landmarks.
Last week, metal fencing appeared around the base of the historic tower, which overlooks Ashton-under-Lyne.
A laminated health and safety notice was put up at the site by Tameside Council which says access to it has been restricted due to concerns 'regarding falling masonry'.
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It is understood brickwork at the top of the structure needs repairing, and that the fencing has been put up as a precaution while surveys are carried out.
A spokesman for Tameside Council said: "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."
Recently readers voted Hartshead Pike one of their favourite things about Tameside.
It is popular spot for afternoon strolls, and on a clear day, visitors can see over four counties, as well as landmarks such as Jodrell Bank, the Welsh hills and the Holme Moss transmitter mast.
