How do I setup a backup system for my home network (2 laptops plus some old desktops) that is fireproof?

I would expect there to be lots of network based backup systems that come in a fire safe; however this does not seem to be the case. I am looking for something that is simple that I can just setup and forget about until I need to recover some data.

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I know there are a 101 internet based solution, however my upload speed is slow and we get capped in the UK if we use to match bandwidth.