photos

If you have a backup on your computer from when the photos were available, you can restore to it. However, it must be a backup taken on your PC or Mac, as iCloud Backup does not contain content that is already synchronized in iCloud.

You can see how to restore from a backup here:

Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

Source, Apple Support:

A computer backup of your device, which is not the same as a sync, includes almost all of your device's data and settings. A backup from a computer doesn't include:

• Content from the iTunes and App Stores, or PDFs downloaded directly to Apple Books
• Content synced from Finder or iTunes, like imported MP3s or CDs, videos, books, and photos
• Data already stored in iCloud, like iCloud Photos, iMessages, and text (SMS) and multimedia (MMS) messages
• Face ID or Touch ID settings
• Apple Pay information and settings
• Apple Mail data
• Activity, Health, and Keychain data (to back up this content, you'll need to use Encrypted Backup in iTunes.)