I know about the Alhambra but I was wondering if there are any other monuments worth visiting in Granada.
I am only in Granada for 3 days so just the best ones.

There are many monuments worth visiting in Granada.
There is a list of the best ones with more information here
https://granadamap.com/places/monuments_to_visit_in_granada.htm
If you are going to do a lot of the monuments it may be a good idea to buy the "bono turistico"
which a ticket which gives you access to several places at reduced cost.
More info here.
https://granadamap.com/bono/
Frequently asked questions about Granada