noun
Refers to a single location, or the same location as previously mentioned or understood. Often used in contexts of staying in one spot or gathering at one place.
See also: 一所 (ひとところ)
彼は一つ所にじっとしていられない。
He can't stay still in one place.
みんな一つ所に集まってください。
Everyone, please gather in one place.