Circles around a location

I have made a page that show concentric circles around a given spot, at 1000 km (or 1000 mile) intervals. Being from a Northern latitude, it's interesting to see that Japan's only as far away as South Africa, which is probably surprising due to the Peters projection that most maps use.

Anyway, you can find it at /static/circles.html. Possible query params are:

E.g. to centre on New York, and use miles, use the following: /static/circles.html?lat=40.7127&lon=-74.0059&miles=true

I might find a better home for it in the future.