Shield volcanoes are large, broad, and gently sloping mountains formed by the eruption of low-viscosity lava. This type of lava flows easily over long distances, creating a wide, shield-like shape. They typically produce non-explosive eruptions, allowing for the gradual buildup of layers over time. These volcanoes are commonly found at hotspots or along mid-ocean ridges. Famous examples include Mauna Loa and Mauna Kea in Hawaii. Their eruptions can create extensive lava fields and are often less hazardous than those of more explosive volcano types, such as stratovolcanoes.