Basel (/ˈbɑːzəl/ BAH-zəl, German: [ˈbaːzl̩]), also known as Basle (/bɑːl/ BAHL), is a city in northwestern Switzerland on the river Rhine. Basel is Switzerland's third-most-populous city (after Zürich and Geneva) with about 175,000 inhabitants. The official language of Basel is (the Swiss variety of Standard) German, but the main spoken language is the local Basel German dialect. In 2019 Basel was ranked the tenth most liveable city in the world by Mercer.