Mountains formed from the build up of volcanic lava often take the shape of a cone.

Here's why:

* Volcanic eruptions: Lava flows out from a central vent or fissure in the Earth's crust.

* Layered build-up: As the lava cools and solidifies, it forms layers upon layers around the vent, gradually building a cone-shaped structure.

* Types of cones: The shape of the cone can vary depending on the type of eruption and the lava's viscosity (its thickness), but the basic shape is often a symmetrical cone.

Some examples of cone-shaped mountains include:

* Mount Fuji (Japan)

* Mount Vesuvius (Italy)

* Mount Kilimanjaro (Tanzania)