A batholith is a large mass of intrusive igneous rock, typically granite, that has crystallized from magma deep within the Earth’s crust. Batholiths are usually exposed at the surface after extensive erosion removes the overlying material. They are significant geological features that can cover hundreds of square kilometers and are often associated with mountain ranges.
Reference: Pitcher, W. S. (1997). The Nature and Origin of Granite. Chapman & Hall.