One of the Mushroom Growers in the Loire Valley, Jacky Roulleau 
of Champignonniere St Maur near Saumur offers a 45 minutes guided tour of his ‘Live Cave of Mushrooms’. You can visit every day from March to October. One of his rising stars is ‘pieds bleus’ (blue feet) mushrooms. They cannot be eaten raw. You can buy some of his products after your visit.
Mushrooms started being grown in the area after the stables of the Cavalry where moved to Saumur.
After spending some time in the caves, you might enjoy a visit to the museum holding the ‘Tapestry of the Apocalypse‘ in Angers.