Heidi (Heidi #1-2) by Johanna Spyri

At the age of five, little orphan Heidi is sent to live with her grandfather in the Alps. Everyone in the village is afraid of him, but Heidi is fascinated by his long beard and bushy grey eyebrows. She loves her life with him in the mountains, playing in the sunshine and growing up amongst the goats and birds. But one terrible day Heidi is collected by her aunt and is made to live with a new family in town. Heidi can't bear to be away from her grandfather; can she find her way back up the mountain, where she belongs?