OT: Hard drive space

Hi

I'm hoping someone can point me in the right direction
My Primary HD has 128.92 GBs used

When I look at the HD there are 4 root folders:

Applications: 10.84 GB
Library: 19.06 GB
System: 4.51 GB
Users: 38.54 GB

Total of those 4 = 72.95 GB

So what I'm wondering is where the other 55.97 GBs are hiding?

Hopefully I'm just being a bit dumb but trying to clear space on the HD is pretty impossible if you can't find out whats taking it up

Any thanks would be very much appreciated

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