Yemen is a country in Western Asia, on the southern end of the Arabian Peninsula. It borders Saudi Arabia to the north and Oman to the northeast and shares maritime borders with Eritrea, Djibouti, and Somalia. It is the second-largest Arab sovereign state in the peninsula. The coastline stretches for about 2,000 kilometers (1,200 miles). Yemen's constitutionally stated capital, and largest city, is the city of Sana'a, but the city has been under Houthi rebel control since February 2015. Its executive administration resides in Riyadh, Saudi Arabia.