Work at Iron Mountain is easy to learn quickly - you'll get plenty of practice because most of the work is so repetitive. This isn't a bad thing - there are many different work areas in which to gain experience.
You are mostly left to work solo so would benefit someone able to use their own initiative.
Salary and benefits, including regular bonus, are fair given the simple nature of the work. However, if your ambition is advancement within the company, you aren't likely to find it here. Positions further up the career chain are few, and management would rather hire outside to fill a position - if they decide to fill it at all. Training is minimal.
Management is a mixed experience, depending on the individual. There is emphasis on big-picture oversight - which is where managerial strengths seem to be. However there is a certain lack of attention to detail when it comes to the day-to-day running of the office. Feedback is slow and often ineffective - though this is common in most multinational organisations.
The people are some of the friendliest I have met and there is a strong sense of camaraderie. Charity and fun events are frequent and help foster friendships between their diverse workforce.
There is strong representation and celebration of minority groups - BAME, LGBTQA+ and neuro-atypical employees feel welcome and looked after.
If you're looking for a fairly paid, none-too-challenging office job, with friendly people, and a clearly delineated work-life balance, I certainly recommend Iron Mountain.