What is 40 km?

It's about 25 miles. Or about 2 hours biking at a steady pace. Or just long enough to travel past:

• a nuclear research facility - Marcoule
  
  


• a hydro-electric power station
  
  


• a village surrounded by an 18th century levee - Caderousse
  


• a tunnel through a mountain for the TGV bullet train
  


• a private chateau - Montfaucon
  


• a strip mine
  


• vineyards as far as you can see