UBS, along with other Swiss banks, owns and operates undisclosed or otherwise secretive bank vaults, storage facilities or underground bunkers for gold bars, diamonds, cash, or other valuable physical assets.[1][214] The geographical location of these facilities are undisclosed to the public but are known to be present in the mountainous regions of the Swiss Alps.[215] These facilities are not subject to the same banking regulations as banks in Switzerland and do not have to report holdings to regulatory agencies.[215][216] According to the Swiss Armed Forces, UBS purchased four former military bunkers to convert into storage facilities throughout the 1980s and 1990s.[201][217] Three of these bunkers are not accessible by road or foot and require aircraft transportation.[201] The transfer of assets to these bunkers is selective as a multi-stage security clearance is required and is not available to all UBS clients.[215] In special circumstances, UBS contracts smaller banks in Southern Switzerland to maintain company assets.[201]