Where are assets downloaded to on Linux? [solved]

I've loaded Linux Mint on my laptop and installed 2017.3 for Linux. It works well so far!

I have made a backup of all my asset store downloads and would like to copy it back. Only problem is: I cannot find where Unity is downloading assets to. :(

Searching on the filesystem has not helped. Checked home, opt, usr/local. And yet, if I download one or two smaller assets, the editor asset store tells me that they are there. Somewhere.

Help would be much appreciated.