Benchmarks in Kilkenny

Anne-Karoline Distel

The tune you just heard is called “The Crow’s Trail”, an original written and performed by me. My name is Anne-Karoline Distel and today, I will talk about benchmarks.

What are benchmarks? Most of you will have seen them. To me, they look like Chinese writing, some refer to them as crows’ feet. The typical benchmark looks like an arrow pointing up with a horizontal line on top. They can look different, though, but more about that later.

Benchmarks were chiselled into walls and stones in Ireland and the UK when the Ordnance Surveys were done. This started in Ireland roundabout the 1830s. The results were published in the 6” map, so 6 inches on paper represented a mile in real life. These maps showed buildings, roads, historical sites, but most importantly acreage, which was essential for taxation. I have heard people refer to benchmarks as “the devil’s mark”. Maybe there is a correlation.

The data for these Ordnance Survey maps was collected by surveyors with surveyor chains and other tools measuring distances and angles in a method called triangulation.

The fundamental reference point for Co. Kilkenny was the spire of St. Mary’s Church in Kilkenny, so it is no wonder, you will find a benchmark there. In addition to calculating acreage, surveyors in the 19th century also tried to keep record of the height above sea level. This is where benchmarks enter the scene. The surveyors calculated the height of a point above sea level in reference to the low water of spring tides in Dublin Bay and the Poolbeg Lighthouse. They left a benchmark at each spot to be able to come back years later and use this exact same spot to check their measurements and calculations.

There are three maps available online which show benchmarks with the height above sea level in feet. The first one is the 5” Ordnance Survey map which was published for Kilkenny in 1871. You can find it on the UCD website looking for historical maps. This 5” map shows most benchmarks of all three maps. The other two are both found on, an initiative of Ordnance Survey Ireland. One is the so called 6” Cassini map, named after the French astronomer Cassini. The third map is the 25” map, finished in 1913. Many of the benchmarks recorded on these maps are gone, because walls have collapsed, bridges have been replaced; many are also simply rendered over and can thus not be seen today.

Now that you know the background, let me take you on a virtual tour of benchmarks along the Medieval Mile in Kilkenny. We start at the Castle. If you’re standing in front of the big entrance gates, the benchmark is to your right about a foot above the pavement. Walk down the Parade to the traffic lights. There used to be a benchmark at the building which is now Ladbroke’s, but rendering makes it impossible to say if it is still there. As you continue along High Street, the next one was at the corner of Friary Street where Woollen Hall was (now Murphy’s Boutique). It is probably hidden behind the fuse box. But don’t worry, you will get to see some eventually! The obvious choice for the 19th century surveyors was the Town Hall. Stay on that side of the street, and the corner column bears one facing High Street. It might be tricky to spot, as it is of the dot type, meaning that the usual horizontal line was replaced by a dot. It is fairly visible on a rainy day. Now go through the Town Hall to the Medieval Mile Museum. As I mentioned earlier, St. Mary’s Church was the fundamental reference point for surveying Co. Kilkenny. The benchmark is on the right hand side of the entrance.

Next stop is Chapel Lane, which is the one next to Carroll’s gift shop on High Street. There is a pair of jostle stones and the benchmark of the dot type is on one of them. Jostle stones, by the way, where put at entrances of lanes, so the wheels of the horse-drawn vehicles wouldn’t damage the wall. To see the next benchmark, you will have to go to court. There were more on the way to the Court House, but they are all lost under rendering or through construction works.

The benchmark at the Court House can be found behind one of the stone benches. Cross the road safely to get to Rothe House. On the left hand side of the entrance arch is a benchmark curiously rotated 90° anti-clockwise. There was actually no rule for the mason of how they were to be chiselled, but this is the only example I know of which is rotated thus. And I have seen 92 so far [137 in total since recording this piece]. If you’d like to continue, go up New Building Lane. On top of that lane, just before you descend the steps to the Black Abbey car park, there is a benchmark in the wall, rotated 180° this time. It is possible that this wall was reconstructed at some point and the stone put back in upside down. The Black Abbey has a benchmark, too. However, it is a bit tricky to spot. When you look at the East window, count the rows of stones to the left of it. In the 4th row from the bottom, you might be able to see it.

Now go towards Freren Gate, but just before passing it, there is a benchmark in the white-washed wall on the right. Reaching Parliament Street, turn left and stay on this side of the street. When you cross the River Breagagh, there is a gate and on the left, you might spot the benchmark.

The last stop on the tour is on top of St. Canice’s steps. Just before you enter the graveyard through the pointed arch, look down to your right and see if you can find it.

These are by far not all of the benchmarks in Kilkenny City; I have found 65 so far with some being inaccessible on private property. But if you enjoyed that and you want to know where to find more of them, you will find additional links in the transcript of this talk on the website of Kilkenny Archaeological Society.

(A map showing all benchmarks found so far (blue drops) with pink drops still needing to be surveyed
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I’m trying to track down all the remaining benchmarks in Kilkenny. If you want to send a picture and location of one you have discovered, please send an email to, and the receptionists will forward the email to me.