Gujarat, India's westernmost state, has varied terrain and numerous sacred sites. In its urban center of Ahmedabad is the Calico Museum of Textiles, displaying antique and modern Indian fabrics. Spiritual leader Mahatma Gandhi's base from 1917–1930 was Sabarmati Ashram, where his living quarters remain on view. The Jama Masjid (Friday Mosque), built in the 15th century, has a huge courtyard and a columned design. Sometimes referred to as the "Jewel of Western India". It has an area of 196,024 km2 (75,685 sq mi) with a coastline of 1,600 km (990 mi), most of which lies on the Kathiawar peninsula, and a population in excess of 60 million. The state is bordered by Rajasthan to the north, Maharashtra to the south, Madhya Pradesh to the east, and the Arabian Sea and the Pakistani province of Sindh to the west. Its capital city is Gandhinagar, while its largest city is Ahmedabad. Gujarat is home to the Gujarati-speaking people of India. The state encompasses some sites of the ancient Indus Valley Civilization, such as Lothal and Dholavira. Lothal is believed to be one of the world's first seaports. Gujarat's coastal cities, chiefly Bharuch and Khambhat, served as ports and trading centres in the Maurya and Gupta empires, and during the succession of royal Saka dynasties from the Western Satraps era. Gujarat was known to the ancient Greeks, and was familiar in other Western centres of civilisation through the end of the European Middle Ages. The oldest written record of Gujarat's 2,000-year maritime history is documented in a Greek book titled The Periplus of the Erythraean Sea: Travel and Trade in the Indian Ocean by a Merchant of the First Century.