Where to go after climbing Mount Kilimanjaro?

Hey !

My boyfriend  and I are climbing Kili in July. After the climb, we want to head to a beach and relax for a week. We are looking for some ideas for where to go. I know that Zanzibar is the obvious choice. I heard its amazing. We are not opposed to it, but just wondering if there any other gems out there!

Thanks for any help.