Who's in the nest?

Hi and welcome to the forum, am not sure who's nest as can't really judge the size ...  here is a page of 7 popular ones
www.woodlandtrust.org.uk/.../

It's on the ground under the bird feeder with holes burrowed around it, I did a video but was too big to upload... its a good 10in wide.

My guess would be Blackbird but far from certain!   You would have to upload your vid to Youtube to get the URL to post here!

10" wide with no bottom and holes dug underneath? Doesn't seem much like a nest. Could it be a Chridtmas decoration carried there and dropped by a fox or something?

I agree with tom, it looks like a Christmas wreath, you can still see bits of Leylandi that hads been used to decorate it.

It's not a Christmas wreath 

It is old/unused, and possibly a blackbird, but whatever made it, it has been taken out of a freshly cut leylandii hedge and placed there.

Interesting indeed. It certainly looks the same as a made wreath.

OK, when I said Christmas wreath, I was thinking of something more like this:

https://www.hobbycraft.co.uk/rattan-grapevine-wreath-20cm/5712641000.html

8 inches across but comes in a variety of sizes.

But the video changes everything. I take it you originally picked up the pot, which had been there for yonks, and found this underneath. The earth has been packed against the rim of the pot and the 'wreath' structure has been worked into the earth implying it was constructed underneath the pot (unless someone put a wreath in a pot and dumped it upside down under the feeder (why?)). Then there are the holes in the ground. Do you have many rats? The holes look too large for mice although both would love the spilled seed under the feeders. Are there droppings? mice are rice grain size, rat are sunflower seed size.