Indoor security grilles on french doors. Anyone got them?

[jalopy]

Our flimsy edwardian french doors are not secure enough and we need to think about installing some internal folding security gates.

Just wondering if anyone has something similar.

Were they were expensive to put in?

Can you hide them effectivly behind curtains when not in use?

Can you have them hinged to the walls instead of the french door frame?

Any info would be helpful, thanks.

What about some really solid internal shutters? Can look rather smart.

or can you put the security gates on the outside of the window?

When will you be using them - daily/nightly or only when out/on holiday? Would you ever want/need to have the windows open and the security grilles shut?