Noun which may take the genitive case particle 'no', Noun
immediately adjacent
食堂はロビーの真隣だが・・・てゆーか、恵子の場所から、あと3歩しかないぞ?The dining hall is directly adjacent to the lobby, or rather, from where you are, it's just three steps away?
Also written 真隣り【まとなり】、真となり【まとなり】