Fetching details from the dictionary...

to be open (to traffic); to lead to; to communicate (with)
to flow (liquid, current); to pass; to get through to
to be understood; to be comprehended
to be honored; to be good
to be well versed in; to be well-informed
to communicate clandestinely; to keep in touch (e.g. with the enemy)
to form a liaison; to be intimate
努力は必ず成功に通ずると信じる。
I believe effort always leads to success.
新しいトンネルが山の向こう側に通じた。
The new tunnel opened a route to the other side of the mountain.
この小道は海岸まで通じている。
This path leads to the coast.