Where are ufos stored?

Nobody really knows. :). However, if you have heard of area 51, you probably know of the conspiracy shrouding it. Many believe that this secret government facility is used mainly for the examination of aliens. Some also believe that they perform autopsies there. Though people know of it's existence, it is strictly forbidden that anyone enters. There are guards in armored vehicles watching your every move as you approach the gate. Most don't know what to believe, but some also say that ufos are stored and worked on there, and that the workers ( which are kept from the outside and not even allowed to talk to their families ) attempt to restore and operate the crashed vehicles. So, until informed, your question is utterly unanswerable.