puncture

Mountains are the geographic feature that most effectively serve as a natural barrier that limits contact between cultures.

Direct contact is when something touches something else without a barrier. This is a term often used in sports like football.

A barrier cream is a topical formulation used in industrial and medical environments. You use it when you want to create a physical barrier between the skin and contaminants which may irritate it and cause contact or occupational dermatitis.

Mountains are often considered a geographic feature that served as a natural barrier between cultures, as they are challenging to cross and can restrict movement and communication between different groups of people. For example, the Himalayas in Asia and the Andes in South America have historically limited contact and interaction between nearby cultures.