Sharepoint - How to delete O365 Team Sites

The link is hidden, and you'd have to type (copy paste it) to reach the delete site option.

Navigate to _layouts/15/deleteweb.aspx in the site you want to delete (as owner). In your case it would be

https://<domain>.sharepoint.com/sites/RobTest/_layouts/15/deleteweb.aspx

It looks like the question was answered but I want to offer another solution (may be newly exposed feature O365 Sharepoint). I too wanted to do the same thing but couldn't find option in normal place (no Site Settings).

HOWEVER, it looks like you can now do so as follows: -go to the group's site -go to Settings menu (cog) and choose Site Information -Delete site option is here

I did this AFTER deleting the actual group through O365 admin so not sure if it would otherwise delete the group but you may have to go delete the group specifically in O365 Admin - Group section.