Any gems that haven’t been discovered by other Brits? A decent lake to swim in is a bonus.

Went to Chamonix this September, nice vibe but a bit busy. Previously loved the Vosges, wondering about the Jura, or more central France? Germany maybe (isn’t the riding a little dull?)

Max drive time from Calais maybe 8 hours plus stops. We did Chamonix overnight which worked well.

Come down to me, millau, south of Massif Central.

Trail running : lots of options. The biggest event in the world for trail running happens here every October. There are about 20 signposted runs.

Mtb : we had ews in 2017, lots of xcountry options too.

Road : hilly but nice scenery.

Swimming : the local swimming pool is an Olympic size, 50 meters. Outdoor. Open end of June till end of August. Couple of lakes 40 minutes drive away.

Plus, lots of parasailing, rock climbing, canoeing, etc..

It is about 10 hours drive from Calais.

Annecy? Went a couple of years ago for road riding, not sure what mtb there is though? Plenty of mountains around there, and a nice lake for swimming.

Annecy is ideal for all of that

The Ardennes would me a good choice.It’s a bit of a hidden gem I think. Lovely scenery, loads of places to stay.
Based around Bouillon, there are loads of MTB and road options on quiet roads, not sure about the Lake though, but there is a really nice wide shallow river running for 50 miles. Loads of canoe/kayak hire places, so I woudlnt think they’d mind a little swimmimng.
Ardennes

My friend has moved south of Annecy , Massif de Bouges region . Rather smart for road and mtb imo.
I visited in October & it was very quiet . We did a 75 km road ride of the local Cols and were passed by less than 100 cars , next day did the vtt stuff around Mont Revard and then local xc stuff .It was grand. I’ve been looking at options for the train and hiring a car for next time….:-)