Himalayas
The Appalachian mountains
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.
The Great Wall of China was built around 220-206 BC under Emperor Qin Shi Huang to protect the Northern boundaries of China.
The Appalachian mountains
Not really. The Great Barrier Reef is a major feature of the Queensland coast. The strait between NZ's two main islands is Cook Strait.
It is the Himalayan Mountain Range that forms a natural barrier between China and India.
The Niagara Escarpment, a long tall cliff that the Niagara falls goes over.
One geographical feature of Brooklyn is Coney Island, a barrier island in the Atlantic Ocean.
Barrier island
The barrier islands
A baymouth bar is a natural feature formed by the accumulation of sand and sediment that creates a barrier between a bay and the open sea. While some human activities, such as construction or dredging, can influence the formation of baymouth bars, they are not primarily manmade features designed to control wave erosion. Instead, they typically result from longshore drift and wave action over time.
The Italian Peninsula is separated from its closest neighbors by several bodies of water, the Tyrrhenian Sea to the west and the Adriatic Ocean to its east, as well as by the central Mediterranean to the south. To the north, the imposing natural feature of the Alps Mountains serves as a significant land barrier between Italy and various central and western European nations.