Igneous rocks initially form beneath the Earth's surface in the crust and upper mantle. Here's why:

* Magma Formation: Igneous rocks are formed from the cooling and solidification of magma (molten rock). Magma forms deep within the Earth due to intense heat and pressure.

* Volcanic Eruptions: When magma reaches the surface through volcanic eruptions, it cools quickly to form extrusive igneous rocks like basalt and rhyolite.

* Intrusive Formation: If magma cools and solidifies beneath the surface, it forms intrusive igneous rocks like granite and gabbro.

So, while we may see igneous rocks on the surface, their initial formation takes place within the Earth's interior.