〜には: as for in / at / for (place, time, person)

に plus は: the place, time or person marked by に becomes the topic, often as a contrast ("here at least", "as for me").

Place + には + あります / います: 駅の前にはコンビニがあります. Person + には: 私には妹がいます (as for me, I have a younger sister). Time: 日曜日には. It keeps the meaning of に; compare では (where an action happens), までは and the plain は. The purpose use (行くには, "in order to") is a later pattern: see には.