I want to access old photos that were backed up on the cloud from 2016. How do I do that?

During that period, were you using iCloud Photos? If so, you can go to iCloud.com and check to see if the photos are there.

Simply from any pc visit iCloud.com where simply by entering your apple id password you can saw ur backuped data and the select year and magically you got your stuff there.

Let tell is it works.