Napoleon's tomb is in the Dome Church. It has layers of tin, lead, mohogany ebony and oak.
There was a WW I & II museum. We got a kick out of the French military helmet with a rooster!
We also enjoyed the EXTENSIVE display of Mideavil armor and weapons.
http://www.invalides.org/pages/anglais/menu_ang.html
http://www.invalides.org/pages/anglais/menu_ang.html