In your own backyard, if you are thinking of “cloud”! 5 floors under ground but above the sea level if you are thinking defense! At the corner of your office’s parking, in a container if you are thinking DR or mobility and so on… There is really no one prescription for this. Location is a derivative of a thorough techno-commercial analysis of the business needs. In many implementations it might be last priority on the list, while in many others it is “the” priority in the data center projects.