What would you do with 1 afternoon in Granada (after the Alhambra in the morning)?

Cathedral de Granada- I would do this but the Albayzin neighborhood is fun to wander if you can find a guide for a walking tour.

A long lunch

My answer is to stay within the Alhambra and see in more detail all the stuff that a half-day tour will gloss over, out of necessity. The Alhambra is IME one of life's peak experiences if savored like a fine wine. Half day, to me, doesn't do it justice.

I, too, spent more than half a day at the Alhambra.

There are many other worthwhile sights in Granada. One that hasn't been mentioned is San Juan de Dios:

photos of (mostly) San Juan de Dios

Another vote for dedicating the whole day to the Alhambra

We enjoyed the Royal Chapel of Granada beside the cathedral more than the cathedral itself. Also, wandering the streets from Mirador de San Nicolás back to Plaza Isabel La Católica, along the river and past El Bañuelo / Baños del Nogal. Beside the cathedral is the La Alcaicería, the old silk market.

We (in our 60’s) spent four days in Granada in October with our son and daughter-in-law (in 30’s), upon moving on to our next stop I asked what they liked best. We saw many of incredible areas and sights already given. Alahambra was #1 and our afternoon at https://granada.hammamalandalus.com/ Hamman al Andalus was #2.

Thank you to everyone for your helpful replies! I think I've got a good tentative plan that I can put aside if we want more time at the Alhambra.

What day of the week? If the weekend then hangout and dance in the square with the locals, watch the buskers and the wedding parties. J