29-Aug-2019 -- While driving back from Luxembourg to Paris (to return my rental car), I decided to make a detour to visit this interesting Degree Confluence Point, which lies on the bank of an island in the Marne River. As previous visitors have noted, you can walk down onto the island from the nearby bridge. At the time of my visit (late Summer), the path along the island was overgrown with vegetation - including stinging nettles. (I was glad that I wore long trousers.) The Degree Confluence Point lies just off the path, down a bank next to the river, just a few metres away. (An empty Evian bottle - not left there by anyone from this project, I hope - happens to mark the spot.)
Although the Degree Confluence Point itself was overgrown with vegetation, I was able to launch my drone from the lawn on the other side of the river - 80m to the East - and fly it above the point. Fortunately, drones are legal in this area (though to a maximum height of 60m only, and over the river and island only; not over the nearby villages.
Here is a remote-controlled aerial video of this confluence point.