The furthest distance one can see from a high place on Earth is determined by several factors, including the curvature of the Earth and atmospheric conditions.
The curvature of the Earth limits our line of sight, meaning that objects beyond a certain distance become obscured by the Earth's curvature. The distance to the visible horizon depends on the observer's height above sea level. On average, the horizon appears about 5 kilometers (3.1 miles) away when standing at ground level.
However, when observing from an elevated position such as a mountain or tall building, the visible distance can be significantly extended. The height of the observer increases the line of sight, allowing for a larger visible radius. For example, if you were standing on a mountain peak that is 1,000 meters (3,281 feet) above sea level, the visible distance to the horizon would increase to approximately 36 kilometers (22 miles).
Keep in mind that atmospheric conditions play a crucial role in visibility as well. Factors such as haze, fog, pollution, and weather conditions can reduce visibility and limit the distance one can see, even from an elevated position.
It's important to note that the concept of "seeing" at extreme distances can also be influenced by other factors, such as the clarity of the observed object, the presence of atmospheric scattering, and the resolving power of the human eye or optical instruments used for observation.