Pink Palace, St Jude and the Great River Road (HWY 61) heading through the river delta and the home of the Blues.
Feel free to DM me for more suggestions and recommendations.
Craig
I have lived here most of my 67 years. Lots of great shots downtown, on the river and in the Mid-town area. I would echo the suggestions for the Beale SPeabody, Sun Studios, Graceland, and Rendevous. There are 2 bridges across the MS river that are lit with LED light that change colors at night.
The Memphis Belle, the WWII bomber, sadly is not here anymore.
There is also Dixon Gardens and Galleries, the Botanic Gardens,
camerapapi, forget Wappanocca for now. I went over there today and they are harvesting timber and many of the trails are overgrown. Saw lots of wildlife but it will be too hard to get good shots with the vegetation so high.
camerapapi
Have lived here most of my 66 years and I am not aware of any waterfalls within an hour drive of Memphis. There are some in Arkansas, such as Blanchard Springs, but they are at least a two or three hour drive.
Reelfoot Lake, mentioned by others here, is great place for migrating birds and cypress swamps. Closer to Memphis you might check out Strawberry Plains near Holly Springs MS or Wappanocca Refuge, AR for migrating birds and the local flora and fauna. Both are a quick 30 minute drive or less.