"Haven", according to the Merriam-Webster Dictionary means "a place offering favorable opportunities or conditions." This, in terms of photos and other dearly held objects, does not include basements or attic spaces.
A recent client brought me down to her (gasp) basement archives. Her own, as well as her in-laws', family photos and memorabilia were stored there. Fortunately, not on the floor. Nonetheless, not a safe haven.
Moisture, mold, heat, damp, plumbing leaks, floods, leaking roofs, squirrels acting squirrelly and mice acting micey - HORRORS!
These destructive elements can happen in a moment or over a longer period of time. We mistakenly believe that our belongings a safely stored up there in the attic or down there in the basement. Tick Tock Rot Rot
FIRST ORDER OF BUSINESS: GET THEM OUT OF THERE!
Until you're ready to EDIT the collection, find an adequate storage area free from moisture or wide temperature fluctuations. Many living floor closets fit the bill. Make room. You know there's plenty of space if you'd just throw some stuff out. Do It. You'll feel better.
Again, until you're ready to EDIT, keep the albums intact and put loose photos in acid free holders or envelopes. Put them all in a lidded plastic storage box. Throw in some silica packets to minimize excess moisture. Yep, save those Silica Do Not Eat thingies that you find with packing materials and pill bottles. They come in handy and they're free, kinda.
Now you've found a haven, at least for your photos!
Next the task of EDTING will be discussed. It's tough. Sometimes you need a professional to get things under control.