Built to protect the government from nuclear attack, this once-secret bunker is now a museum and National Historic Site of Canada.

A "doomsday" seedbank under construction on the Norwegian island of Spitsbergen in the remote arctic Svalbard archipelago.

NY Times article discussing a road tunnel that converts to a bunker big enough for 21,000 people

The mission of the Frozen Ark Project is to collect, preserve and store DNA and viable cells from animals in danger of extinction. Could be used as a model for a project including all animals, in case of a global cataclysm.

and how they are part of an active Doomsday Machine, like in Dr Strangelove

Russia has been constructing a massive underground facility at Yamantau Mountain, large enough to house 60,000 persons