The Great Laxey Wheel has begun turning again, almost a year after it was stopped due to structural damage.
Manx National Heritage said the wheel was able to be restarted following the completion of safety checks and increased water levels.
Built in 1854, the 72ft (22m) diameter wheel is the largest working waterwheel of its kind in the world.
A MNH spokeswoman said the group was "absolutely delighted" to see the wheel turning "gracefully" once again.
The wheel was stopped in August last year after engineers found a problem with a large timber rod, which connects to the main crank, during routine checks.
The Victorian wheel, which was originally used in mining, was restarted on Saturday morning without the rod in place.
Tests had been carried out to measure the amount of water needed for the wheel to turn without the full mechanism in place.
Known as the Lady Isabella, the wheel is currently open to the public from Saturday to Wednesday.