Today I tested out the route around the lake. And in the process managed to run about 6km - another personal record.
I did not run all the way around - I started with a brisk walk for the first half km, and also got lost and had to pause to consult my map. But I did make it all the way around, a little less than 7km.
So my goal of running all the way is still there, waiting for me. But I am much more confident that I can do it. I have a better idea of the route, and a feel for where the hills are.
Anyway, here's another photograph of it.