Bahrain is an archipelago of 33 islands, the largest being Bahrain Island, at 55 km (34.2 mi) long by 18 km (11.2 mi) wide. Saudi Arabia lies to the west and is connected to Bahrain by the King Fahd Causeway. Qatar is to the southeast across the Gulf of Bahrain. The planned Qatar Bahrain Causeway will link Bahrain and Qatar and become the world's longest marine causeway.
Known for its oil and pearls, Bahrain is also home to many large structures, including the Bahrain World Trade Center and the Bahrain Financial Harbour, with a proposal in place to build the 1022 m (3353 ft) high Murjan Tower. The Qal’at al-Bahrain (the harbour and capital of the ancient land of Dilmun) was declared a UNESCO World Heritage Site in 2005. The Bahrain Formula One Grand Prix takes place at the Bahrain International Circuit.