Welcome to the Q&A Forum

Hey, The rule of fist is that readability is the most important aspect of your URL. The /category/ folder does not add to relevance, neither does it make the URL easier to read. I would therefore say it's better to remove the folder. I guess you don't use the /category/ folder as a page itself and have the visitor land on /destinations/ right away? As long as the content on your /africa/ page is valueable and unique, I wouldn't remove that. I hope this answers your question!

put the domain to see the error please