Chamonix - 50m - only real problem is the ride in / out. It's safe but you have to go one way or t'other to get to a bigger variety BUT running is awesome
Grasse / antibes - two 50m pools. Grasse is outdoors and bluntly its the best riding I have ever come across
My sister in law does mallorca. Check out what pools are there but she swears the riding is just the best. May be a bit hot
Sion -
https://www.valais.ch/...-pool-l-ancien-stand More riding than you can shake a stick at there and you can act out scenes from Heidi or the sound of music
If Switzerland a bit pricey but you can do; verbier, grand and petit Bernard, forclaz, lac emosson etc
Back to France
http://megeve.com/...rself/sports-center/ Megeve is really cool. Solves the problem of getting out of the cham valley (I'd always stay in cham but that's by the by)
Running anywhere above is amazing
As is the riding
The othe t great place is morninf. Don't know what the pool situation is but the riding, running and general atmosphere is super cool