Willemstad is the capital city of Curaçao, an island in the southern Caribbean Sea that forms a constituent country of the Kingdom of the Netherlands. Formerly the capital of the Netherlands Antilles prior to its dissolution in 2010, it has an estimated population of 150,000. The historic centre of the city consists of four quarters: the Punda and Otrobanda, which are separated by the Sint Anna Bay, an inlet that leads into the large natural harbour called the Schottegat, as well as the Scharloo and Pietermaai Smal quarters, which are across from each other on the smaller Waaigat harbour. Willemstad is home to the Curaçao synagogue, the oldest surviving synagogue in the Americas. The city centre, with its unique architecture and harbour entry, has been designated a UNESCO World Heritage Site.