For a while, I’ve wanted a way to view megaliths easily from my phone. The more-or-less definitive resource for British megalith sites is https://megalithic.co.uk. Whilst this is an exceptional trove of knowledge, the browsing experience is somewhat sub-par. Similarly, there is http://www.stone-circles.org.uk. The browsing experience and quality of data on this site are better than megalithic (simply due to it being curated), but still lacking.
My basic requirements for a new system are that:
- It should show the locations clearly. This means no “15 sites at this location” prompts, which both of the above sites have due to using Leaflet to display their data.
- It should be integrated with an existing mapping tool. I often plan hikes around these sites, and frequently want to be able to see what’s in my vicinity.
- The data should be somewhat curated. I don’t care about sites that are destroyed, or sites that are documented with no further evidence.
I use two map applications on my phone: Organic Maps and OsmAnd. Compatibility with either of these is good enough for me.
My initial plan was to target OsmAnd, in a similar way to how the UK postcodes POI work. This was largely unsuccessful though, as converting to OBF is not amazingly documented (I was always getting empty files).
I then moved to GPX. I have used GPX in the past for plotting routes, but didn’t appreciate that GPX is also ideal for making collections of map markers. Furthermore, creating a GPX file is incredibly easy, and compatible with both OsmAnd, Organic Maps, and a plethora of other mapping systems.
My final product is megalith-osm. This is a Python
script that downloads and caches data from both sources, and produces a GPX. It deduplicates against
the name and location, removes museums and modern stone circles, and filters by “quality” (specified
by the -q argument). Quality varies from 5 to -1, where -1 is destroyed and 5 is “perfect”.
Using -q 5, we get 1182 sites. Using -q 1, we get 15,846 sites. On my own device, I have opted
to use -q 5.
You can download the -q 5 file from Downloads. Thanks!