A balancing rock, also called balanced rock or precarious boulder, is a naturally occurring geological formation featuring a large rock or boulder, sometimes of substantial size, resting on other rocks, bedrock, or on glacial till. Some formations known by this name only appear to be balancing, but are in fact firmly connected to a base rock by a pedestal or stem.

A climbing wall is an artificially constructed wall with grips for hands and feet, usually used for indoor climbing, but sometimes located outdoors. Some are brick or wooden constructions, but on most modern walls, the material most often used is a thick multiplex board with holes drilled into it.

Games played with curved sticks and a ball can be found in the histories of many cultures. In Egypt, 4000-year-old carvings feature teams with sticks and a projectile, hurling dates to before 1272 BC in Ireland, and there is a depiction from approximately 600 BC in Ancient Greece, where the game may have been called kerētízein or because it was played with a horn or horn-like stick. In Inner Mongolia, the Daur people have been playing beikou, a game similar to modern field hockey, for about 1,000 years.