| Tuff rings and cones resemble maars, but they have higher rims and are not filled with water. |
| Most maars have low rims composed of a mixture of loose fragments of volcanic rock and rocks torn from the walls of the diatreme. |
| Maars are volcanoes formed by the violent interaction of red-hot magma coming into contact with groundwater. |
| The maars of the volcanic district of Eifel in Germany are among the best known of these formations. |
| The latter are termed maars, following the local name for such forms in Germany. |
| Canada has examples of almost every type of volcano found in the world, including stratovolcanoes, shield volcanoes, calderas, cinder cones, and maars. |
