The phrase "walls off" implies creating a barrier or separation, but its antonyms can convey a sense of openness and connection. Words like "unify," "merge," and "integrate" suggest a desire for unity and the breaking down of boundaries. Other antonyms include "link," "connect," and "join," all of which suggest the bringing together of separate entities. "Bridge" and "span" suggest creating a connection where none existed before, while "reach out" suggests a willingness to extend oneself and form relationships. Overall, the antonyms for "walls off" convey a sense of openness and inclusivity, whereas the original phrase suggests exclusion and separation.