Why do you want to visit Saint Lucia ?
I don't know how to answer his question while I have some options for it like livley festival , spectacular scenery, lots to do, lively festival! actually I don't know how to use them in my answer!
Thanks

Question

Why do you want  to visit Saint Lucia ?
I  don't know how to answer  his question while I have some options  for it like livley festival , spectacular scenery, lots to do, lively festival!  actually I don't know how to use them in my  answer! 
Thanks

Answer

How about these:

"I want to visit Saint Lucia because of the spectacular scenery and lively festivals."

"I want to visit Saint Lucia because there are lots of things to do there."

"I want to visit Saint Lucia because of its lively festivals, spectacular scenery, and multitude of fun things to do."