Keen-eyed Montrealers may have noticed some of the controversial art installations in Mount Royal Park are fenced off.

Three of the granite stumps, installed this year at a cost of $3.45 million, are surrounded by fences while the entrepreneur that installed them makes "corrective" changes to them.

A spokesperson for the city of Montreal said the changes being made are minor, such as putting down grass around the sites, and are being paid for by Aménagement Côté Jardin Inc., the company that was awarded the contract by the city last May.

The installations are part of a $3.45 million project called Discovery Halts, which was commissioned for Montreal's 375th anniversary. The project faced some controversy due to its hefty price tag.

The fences are expected to remain up for a few more weeks.