OpenStreetMap
It seems I have developed a reputation in Ireland and the UK about my history mapping, because SK53 had tagged me in a toot about Martello towers. At first, I somewhat brushed it off, but as he probably knew, my interest was eventually triggered and I looked into the matter.
I remember that DeBigC was the first to tell me about Martello towers, but I can’t remember if he used a specific example or just shared his interest.
For those who aren’t familiar: Martello towers were built by the British Empire at a time when they were still ruling the waves, especially around the time of the Napoleonic Wars, when there was a threat of a Napoleonic invasion into British territory. They continued building them in port towns, so mostly along the coast, but not all of them are coastal. Apparently (according to Wikipedia), they are usually round and built in two levels with the guards living in it (i.e. building). They placed a cannon on the top which had a 360° reach, although one hopes that they only pointed it seawards.
The good news was that a lot of them were already mapped on OpenStreetMap, mostly with name=Martello Tower. The bad news (as pointed out in the toot) was that there was no consistent tagging scheme. Most of them were mapped as man_made=tower, and some had some sort of historic tag on them (ruins/ castle/ yes etc), but few were mapped as buildings. So, I came up with historic=martello_tower, skipping the proposal process and documented the tagging scheme in the wiki.
(You might want to debate whether tower:type=watchtower or tower:type=defensive applies, but since a watchtower isn’t necessarily limited to military use, I went with defensive.)
A cannon on the restored martello tower on Mauritius
I first tidied the ones in Ireland and the UK. Judging from OSM, Ireland is the country with the highest density of martello towers, but I’m not sure if that is/ was true at the time when they were still in use.
I also looked at Wikimedia where a lot of them are documented. They seem to have quite a fanbase. I also tidied up the categories on Wikimedia, while I was at it.
This led me to look at the martello towers further abroad like North America, Mauritius, Bermuda, India, Australia etc.
If I remember correctly, the martello tower at Fort Denison was the last one to be constructed.
Not all the ones named “Martello tower” fall under the above definition. There was one example on wikimedia in North Africa which had been built by Governor Haji Sharmarke Ali Saleh, and the photograph didn’t look at all like a martello tower, so I left that one alone.
There are now 92 mapped on OSM (overpass); I don’t know if that is all the surviving ones ore not.
(On a side note, especially to DeBigC - I wonder if all the Irish and UK ones have benchmarks on them!)
Discussion
Comment from EdLoach on 3 October 2023 at 08:07
I have updated three more in Essex this morning from historic=tower to historic=martello_tower, adding building=tower if that was missing. In case they need any other tidying they are https://www.openstreetmap.org/way/129126566 https://www.openstreetmap.org/way/288480830 and https://www.openstreetmap.org/way/72501575
Comment from b-unicycling on 3 October 2023 at 17:19
Thanks for those, EdLoach. According to the number on Wikipedia, only half the number of originally built martello towers is on OSM, but I don’t know how many actually survive. Some might have fallen victim to coastal erosion already.
Comment from b-unicycling on 3 October 2023 at 17:21
Comment from b-unicycling on 3 October 2023 at 17:21
Comment from EdLoach on 4 October 2023 at 08:41
SK53 mentioned that I’d been trying to locate Tower J in one of the Mastodon toot’s you were tagged in, which was after I read on Facebook about where local tradition says it is (which seemed unlikely to me). The post appears to be in a public group. I discovered this interesting document about the Martello Towers on the east coast of England, and a Google books result suggesting it was sold in 1834 in grounds of 6.5 acres, so was trying to find maps surveyed between roughly 1805 and 1834 which might have shown it. I found earlier and later, which I added as links in replies to one of my comments on the Facebook post. The Facebook post comments also suggest the land was used to expand Walton-on-the-Naze, and the bricks were used in various buildings (Martello Cottage and 1, 3, 5 Newgate Street in 1836).
It seems strange to me that towers G, H and I only survived until 1819.
Tower B was demolished in the 1970s (according to one site I read) and before that was in private ownership and was used for a time as a radio astronomy observatory, with photos on the 5th page of this article about Frank Hyde and based on side by side maps at NLS that show the tower, it would have been about here.
Comment from Kioska Journo on 8 October 2023 at 13:05
About the Corsican towers which inspired Martello towers, I faced the same decision, and I failed to choose one tag scheme. Thanks for the post ! I think now that a tag historic=genovese_tower would be appropriate.
Comment from ChristianSW on 8 October 2023 at 16:24
Hi! Here you will find lots of information and photos:
https://www.geograph.org.uk/of/martello
Comment from Adrion on 9 October 2023 at 22:21
A couple of years ago I did some casual research and tried to make sure that all of the surviving Martellos along the South and East coasts of England were on OSM and named with their original reference number/letter(s). I also added any other relevant info that I randomly gleaned, but I changed as little as possible of whatever tagging was already done, and it’s really nice to see other people making it better and more consistent.
The best resource I found was Peter Faulkner’s website. It seems to be down at the moment but there’s an archived version from May here - it was a mine of information, though it looks like the pictures don’t work in the archive.
All the best!
Comment from b-unicycling on 9 October 2023 at 23:10
I was pleasantly surprised that almost all, if not all martellos were mapped in some shape or form.
I was actually wondering whether we should have a
ref:martellofor all the numbered ones in the UK and Ireland, even though some numbers might overlap, mayberef:IE:martelloandref:UK:martello.Comment from Adrion on 10 October 2023 at 15:31
I only know anything about the English ones. For them, my attitude was that the number/letter is their historical name (at least to us now) rather than a behind-the-scenes ID, and I wanted to treat it as a name. (Sometimes I had to give precedence to a modern use, e.g. museum name.)
I like it that the letter/number might be rendered as a name on the map. Since it’s a linear spatial sequence (with some missing) it helps to indicate where in the chain you are and where others may be. For people who don’t know the history, it might draw them in to find out that a Martello doesn’t exist in isolation. If the letter/number were only in a ref tag, then not only would it be unlikely to be rendered but a general purpose international map might reasonably not include this data at all.
But then, I’m aware that I have a bias to tag in a way that will be most useful to people who use maps the way I do!
Comment from osmuser63783 on 3 November 2023 at 19:14
Great post! I’ve added the tag to Jersey’s Martello towers. Now we just need a tag for the earlier round towers in Jersey that are commonly called Martello towers but precede the “true” ones by two decades… https://www.theislandwiki.org/index.php/Coastal_towers