Turnberry's Ailsa course will be 247 yards longer for this year's British Open than it was the last time it staged the event in 1994.
Six new tees have been built, extending the layout from 6,957 to 7,204 yards, organisers the Royal & Ancient (R&A) said at a news conference on Tuesday.
The biggest change in distance is at the par-five 17th hole, stretched from 498 to 559 yards.
There has been a major re-design of the 16th, with a straight fairway changed to a left to right dog-leg and new dunes and hollows created near the burn in front of the green.
A dramatic new tee at the 10th has been constructed on a rock outcrop near Turnberry's iconic lighthouse and the drive now demands a 200-yard carry over the bay.
R&A officials also said they were confident the refurbishment of the hotel at the Ayrshire course would be finished in time for the July 16-19 championship.
The hotel, bought by Dubai-based Leisurecorp last year, is undergoing a multi-million pound overhaul and is blighted by scaffolding.Reuse content