The national flower of Estonia is the cornflower, which has grown in the country's soil for over 10,000 years. The national bird is the barn swallow, whose call can be heard from barns across the country. Estonia has a population of around 1.3 million people, with its capital and largest city being Tallinn. The country uses the Euro as currency and speaks Estonian as the primary language, where "tere" means hello. Forests cover 46.4% of Estonia's land and it has the cleanest air in the world according to WHO rankings.