Seashells are usually found on beaches. How have some ended up at the top of this mountain? People and places -Physical geography - Mountains Learning Points A mountain is an area of land that is significantly higher than the land around it. The height of an object in relation to sea level is known as its altitude. A Twig Curriculum Film. Delivering key learning points. Get straight to the facts in just three minutes – directly linked to core learning, Twig's curriculum films will fit neatly into your lesson plans.