Sharjah, which shares its southern border with Dubai, is ruled by the Al Qasimi family. It is approximately 2,600 square kilometres and is the only emirate to have coastlines on both the Arabian Gulf and the Gulf of Oman. In the nineteenth century the town of Sharjah was the leading port in the lower Gulf. Produce from the interior of Oman, India and Persia arrived there. Sharjah's salt mines meant that salt constituted an important part of its export business, along with pearls. In the 1930s when the pearling industry declined and trade decreased due to the creek silting up, Imperial Airways' flying boats set up a staging post for flights en route to India, which benefited the residents of Sharjah. Today, under the leadership of Sheikh Sultan bin Mohammed Al Qasimi, Sharjah is the cultural and educational centre of the UAE and takes pride in preserving the country's cultural heritage as well as promoting Arab culture and traditions.