BookRetreats.com has created the Global Relaxation Index to find the world’s most relaxing destinations. Based on the analysis of nine metrics, the study scores 76 countries across key categories including safety, solitude, serenity, nature, and wellness. In Estonia, once you get out of the city, nature takes over. It is abundant, beautiful and works on its own timetable. It literally forces you to relax. Here are twenty of the world's most relaxing holiday destinations.