Which archaeological discoveries are kept secrets by governments?

Some archaeology discoveries are kept secret.in different scenarios. If national safety is a factor, a finding or even a search will be kept secret and rightly so. There have been many discoveries kept secret in the past. Sometimes, it is just to prevent looting but other times, it is much more involved. Lyndon B. Johnson signed the Preservation Act into legislation which entailed that artifacts could be kept secret if need be.

There are times the public might even panic over findings which means it is a protection of sorts for this type of secretive work to go on. Other times, it can be covering up conspiracy theories and such. Not all discoveries are shared and it is probably best that way.