From last September if you live in Toulouse you can visit some local museums free on the weekend. All you need to do is to register in the City Hall (Place du Capitole). Don't forget to bring with you your ID card, a proof of residence and a photo. After that you can visit free the following museums:

• Muséum d'histoire naturelle (the Maourine gardens too)
• Musée des Augustins,
• Musée Saint-Raymond
• Musée Paul Dupuy 
• Musée Gerorges Labit
• Conventual of the Jacobins,
• the Roman amphitheatre of Purpan
• the archeological crypte de Saint-Pierre-des-Cuisines

Note that the card enables to you visit only the permanent exhibitions, the temporary ones remain payable.

Don't mix this initiation with the Free Museum on the first Sunday of the month, that is nationwide, and allows every visitor to visit the permanent exhibitions of the participant museums.

For more info visit:

http://www.cultures.toulouse.fr/-/museelibre-les-musees-gratuits-le-week-end-