谷底

1. Origins, structure, and basic meaning

• Structure: 谷底(たにぞこ) means the floor or lowest part of a valley.
• Basic usage: It is used for objects rolling down or sounds heard from below in a valley.

2. Common pitfalls and similar expressions

• An endpoint and the source of a sound
  • 谷底まで means as far as the valley floor, marking where the pebble reached.
  • 谷底から means from the valley floor, marking where the river's sound comes from.