An approx. 45km circumnavigation of Lac du Bourget, the deepest natural lake in France.  Mostly fairly flat, but with some hills on the western side.

SALOMON DE CASIMACKER submitted this route:

https://www.visitisleofman.com/things-to-do/activities/walking-and-hiking/raad-ny-foillan-coastal-footpath

The Raad ny Foillan, Manx Gaelic for ‘The Way of the Gull’, is the Isle of Man’s premier long distance footpath. At almost 160 km / 100 miles in length it provides the perfect opportunity to walk around a complete Nation!

The Markermeer Loop is a very popular route around the Markermeer Lake, north of Amsterdam. It's mostly done by road cyclists but this addition here at FKT will be for walking / running attempts. The route follows the edge of the lake for its entirety, and is fully connected except for the 300m across the river IJ, and that's why the route starts north of the Amsterdam Centraal Station (on the north side after taking the pond) and finishes at Centraal Station ferry docks.

It's also an exact 160km (100miles), which makes for an interesting flat attempt at the distance.