안녕하세요 닉씨 ^^
좋은 질문인 것 같아요!
보통 '-을'은 목적어를 만들 때 사용이 되요.
이 문장에서 '여행'은 목적어로 사용이 되기 때문에 '-을'이라는 전치사가 함께 쓰였답니다!
Hello Mr. Nick,
Thank you for you question and it's good!
In general, '-을' is used to make the noun or so to be the object.
In this sentence, the travelling is used as the objective, it's right to add preposition which is '-을' in the end of 여행.
Hope this helps a bit and please let us know anytime you have more questions!
Just subtitled a bit in case!
Thank you
Madison
Team Koreanclass101.com