Breakdown of Naar welk asiel gaan jullie morgen?
jullie
you (plural)
naar
to
morgen
tomorrow
gaan
to go / to go off (of an alarm)
Questions & Answers about Naar welk asiel gaan jullie morgen?
Why is it welk here and not welke?
Because asiel (shelter) is a het-word (het asiel). When you use the word for 'which' with a singular het-word, you drop the -e and it becomes welk. If it were a de-word or plural, you would use welke.
Could I say wat voor een asiel here instead?
You could, but it changes the question. Welk asiel asks for a specific choice from a known group ('Which shelter?'). Wat voor een asiel asks about the category or type ('What kind of shelter? A dog shelter?').
Why does the sentence start with naar?
In English, it is common to put the preposition at the end of a question ('Which shelter are you going to?'). In Dutch, the preposition must stay directly in front of the question phrase ('To which shelter...'), making it Naar welk asiel.