What you see is a 'switchboard.' Not to be confused with something used by snippy women at the phone company in days of yore, both 'switchboards' and 'switchgear' are commonly found in industrial and commercial locations.

Each of those big switches is the disconnect for some major load - a motor, air conditioning, a panel. Inside each compartment ("bucket") there are usually fuses.

You were correct in not opening the compartments. First off, they're designed not to open with the switch in the "on" position. Secondly, there are a number of different mechanisms for turning them back 'on;' often you can't simply flip that switch. Finally, even in "off," there are large parts within that remain energized.