To ask your spanish friends where are they going to spend their holidays you must say:

Donde vais a pasar las vacaciones?
(Where are you going to spend your holidays?)

To this question they might answer:
-En la playa (in the beach)
-En la montaña (in the mountain)
-En el pueblo (in the village, sometimes they might refer to their hometown)
-En ninguna parte, nos quedaremos en casa
(we'll go nowhere, we'll stay home)