1. Mid-Ocean Ridges: These are underwater mountain ranges formed by the upwelling of magma from the Earth's mantle. As the magma cools and solidifies, it creates new oceanic crust, pushing the plates apart.

2. Rift Valleys: These are deep valleys that form on land as the crust is pulled apart. As the land stretches, it thins and fractures, leading to the formation of these valleys. The East African Rift Valley is a prime example.

3. Volcanoes: Divergent boundaries are sites of volcanic activity as magma rises to the surface. This magma often erupts through fissures and cracks in the crust, creating chains of volcanoes. Iceland, for example, is a volcanic island formed by the Mid-Atlantic Ridge.