1The main entrance or front gate of a building, school, shrine, or other facility.
学校の正門で待ち合わせしましょう。
Let's meet at the school's main gate.
正門は夜9時に閉まります。
The main gate closes at 9 p.m.
お城の正門をくぐって中に入った。
We passed through the castle's main gate and went inside.
正門から入らずに、裏口を使った。
Instead of entering through the main gate, I used the back door.