Any electricians out there?

[Wingedharpy]

I have this ugly monstrosity in my porch.
I have no idea what it's for (other than it's something to do with earthing electrics).
No electrician who has visited the house to do work has ever looked at it AFAIK.
Can I box it in so I don't need to look at it, or not?
If not, why not?
Many thanks.

It is the service head for the incoming supply, and company fuse, and the supplier earth. Into it goes the supply cable, (usually out of the ground but sometimes overhead), and out if it go the (usually two) cables to your electricity meter, and the green and yellow earthwire that goes to your Main Earthing Terminal, which is probably inside the consumer unit, but might be a substantial metal block.

You can cover if up with a door if you want, but it must be readily accessible for inspection and infrequent maintenance.

Stand back and take a wider view pic please.

Well now, this is where it gets tricky.
I can't take a wider view as it's in a tiny porch and I was up a ladder taking that pic.as the unit is at ceiling height - high ceiling.
You have described the wiring set up perfectly PigletJohn.
There is a fat pipe type thing which comes up through the floor and runs up the wall to the black plastic box thingummybob.
I suspect this is the supply cable, wrapped in some sort of stuff (possibly asbestos wrap).
I should also fess up here and say that I have already boxed it in but it just dawned on me that I maybe shouldn't have!
Boxing is easily removable if anyone wants to look at it.
No one has ever looked at it or examined or inspected it in the 30 odd years we've lived here.
Sods law says someone will come next week and want my Blue Peter'esque boxing removed.