A public park — an outdoor public space with greenery for walking, recreation, and picnics (occasionally written 公苑 in park names).
子どもたちは公園で元気に遊んでいる。
The children are playing energetically in the park.
休日に友達と公園でピクニックをした。
I had a picnic in the park with friends on the day off.
この公園は夜は閉まるので、時間に注意してください。
This park closes at night, so please pay attention to the hours.