The Islington Tunnel on the Regent’s Canal underwent a vital check-up on Tuesday, with engineers from the Canal & River Trust surveying the four million bricks that make up the underground structure.

The last repairs for the 200-year-old tunnel, which links King’s Cross with Angel, took place in 2000.

The Trust took a whole day to make the inspection, with engineers using a boat to assess any structural changes to the tunnel, including checking for cracks and identifying any restoration work required.

Florence Salberter, Canal & River Trust heritage advisor, said: “Islington Tunnel is an amazing piece of London’s heritage. The bricks inside were handmade and put in place two centuries ago, given the technology available in those times it’s amazing to stop and think of how much was achieved. Today, going inside is like stepping back in time. The confined space means you’re travelling through this dark, quiet tunnel, even though you are right under the hustle and bustle of Islington.

“Because of the age of the tunnel, its location and depth, it’s important we give it an MOT. It’s obviously such a crucial part of the canal network in London – connecting the east end of the Regent’s to the west, and beyond that the Grand Union which continues up to Birmingham. The Regent’s Canal is arguably more popular than ever before and this is a good example of the type of work needed to keep it in top shape.”

You can find out more about the Canal & River Trust here.