How to create contour plot that is not located in the xy-plane?

I wish to place two plots perpendicular surface plots (xy-plane and xy-plane) in the same figure. Using surf this can be done easley but I would like to show some fixed contour levels as with contourf. Contourf however always plots the data in the xy-plane. Can contourf plot the data in for ex. the xz-plane instead or can the surf command be used to show fixed levels as contourf?