Caen Hill Locks: The story behind the canal which linked Bristol to London in the 1800s
Wiltshire is home to one of the UK's most spectacular feats of engineering - Caen Hill Locks.
It was built more than 200 years ago and remains one of the longest continuous flights in the country.
Going through each of the 16 locks takes around five hours - and is seen by many boaters as the ultimate challenge.
So as canal boating companies say they have seen bookings soar amid a rise in demand for so-called 'staycations', ITV West Country presenter Kylie Pentelow went to investigate the impressive feat of engineering...
Watch Kylie Pentelow's special on the Caen Hill Locks
Caen Hill Locks - a rich history
Constructed in the early 1800s, the lock stretch on the waterway was originally used to connect Bristol to London and other major cities through canals.
"If we go back 220 years, this was the freight super highway," said Morgan Cowles, who is heritage and environment manager for the locks.
He told Kylie: "This was the fast lane to move 60-tonne barges between Bristol and Bath in the west and to Newbury and Reading in the east.
"So to us now, we're going at a slow pace, but to them this represented the quick route."
In its heyday the canal was gas-lit so it could be used 24 hours a day - but when railways were introduced, the route fell into disrepair and it eventually closed in 1948.
It would not be until the 1980s the locks would be refurbished and reopened, thanks to the tireless work of volunteers.
How do the Caen Hill Locks work?
The lock chambers act like a "large bath" with plug holes at each end, according to lock keeper Bob Preston.
The sluices are opened and closed to allow water in and out, allowing boats to rise - or fall - to meet the height of the water at the next lock.
Each lock sits at a different level and volunteers on land help to open and close the gates as boaters navigate through them.
Once the water is let out of the gates, it naturally goes back downstream but since 1996 the water has been able to be pumped back upstream so it can be recycled.
Caen Hill Locks is one of the longest flights in the country, dropping more than 230ft.
Even now, many experienced boaters consider navigating the stretch as one of the ultimate challenges - and it takes a little more than five hours to go through all of them.
Volunteers help to keep the locks in use, but opening and closing them is no easy task.
Husband and wife Mick and Karen Tunstall have been volunteering as lock keepers for nine years, having decided to take on the challenge to keep fit.
"[The gym] was costing about £800 or £900 a year and then the guys wanted volunteer lock keepers so we decided 'let's try that' and we did this instead," said volunteer Mick Tunstall.