A hot-air balloon — a large balloon that floats by filling it with heated air; often used for sightseeing rides and ballooning events.
熱気球に乗って山の上から景色を眺めた。
I rode a hot-air balloon and viewed the scenery from above the mountain.
毎年、近くの公園で熱気球のフェスティバルが開かれる。
Every year, a hot-air balloon festival is held at the nearby park.
パイロットがバーナーで空気を加熱すると、熱気球はゆっくり上昇した。
When the pilot heated the air with the burner, the hot-air balloon slowly rose.