We started an exploration into the unknown world.

We decided to explore the unknown forest.

My father found an old stock certificate.

My friend is participating in a clinical trial for a new drug.

We are planning to travel outside of the prefecture next week.

We traveled across the prefectural borders.

After a long journey, we finally arrived at the county border.

The hustle and bustle of this city calms my mind.

This city is always noisy, there is no quiet time.

The ticket inspector was checking the passengers' tickets on the train.