In theory, it is possible for a place to be so dark that light cannot penetrate it. This concept is often referred to as "absolute darkness" or "complete darkness." However, achieving such extreme darkness in reality is challenging.
In our everyday experience, we encounter varying degrees of darkness, but there is almost always some ambient light present. Even in a pitch-black room, there might be small amounts of light coming from electronic devices, cracks in doors, or other sources.
To create a place where light cannot shine through, you would need to eliminate all sources of light and prevent any external light from entering. This would involve sealing off the area completely, blocking all openings and preventing any light from entering or reflecting into the space.
In addition, the surfaces within the enclosed area would need to be extremely efficient at absorbing or diffusing light. Most materials reflect or scatter light to some degree, even if it is minimal. Achieving a truly light-absorbing environment would require using specialized materials that can effectively absorb all wavelengths of light, such as Vantablack, an artificially created substance that absorbs over 99.9% of visible light.
While it may be challenging to create a place of absolute darkness, researchers and scientists often work with highly controlled environments, such as darkrooms or anechoic chambers, to minimize external light and sound as much as possible for specific experiments or studies.