Here's a very easy art idea using stuff you probably already have. We used charcoal pencils to make the mountains, and colored pencils for the details. Start by putting two pieces of paper over each other and fixing the top. Use a clipboard or tape. Tear a bit off the bottom of your top sheet to makes your smallest mountains. Then draw along the tear. If you have pencil or charcoal smudge it down. Keep tearing the top sheet and adding layers. Then add castles or other cool stuff to your mountains.