Tel Aviv-Yafo (Hebrew: תֵּל־אָבִיב-יָפוֹ) (usually Tel Aviv) is the second-largest city in Israel, with an estimated population of 384,400. Tel Aviv is situated on the Israeli Mediterranean coastline, covering 51.8 square kilometres (20.0 sq mi). It is the largest and most populous city in Israel's largest metropolitan area known as Gush Dan, home to 3.15 million people as of 2007. The city is governed by the Tel Aviv-Yafo municipality, headed by Ron Huldai.
Tel Aviv was founded in 1909 on the outskirts of the ancient port city of Jaffa (Hebrew: יָפוֹ, Yafo). The growth of Tel Aviv soon outpaced Jaffa, which was largely Arab at the time. Tel Aviv and Jaffa were merged into a single municipality in 1950, two years after the establishment of the State of Israel. Tel Aviv's White City, designated a UNESCO World Heritage Site in 2003, comprises the world's largest concentration of Modernist-style buildings.
Tel Aviv is Israel's economic hub, home of the Tel Aviv Stock Exchange and many corporate offices and research and development centers. Its beaches, cafes, upscale shopping and secular lifestyle have made it a popular tourist destination. It is the country's cultural capital and a major performing arts center. In the 2007 Mercer cost of living survey, Tel Aviv was ranked as the most expensive city in the Middle East and the 17th most expensive in the world.