Yemen (Arabic: اليَمَن al-Yaman), officially the Republic of Yemen (Arabic: الجمهورية اليمنية al-Jumhuuriyya al-Yamaniyya) is an Arab country located on the Arabian Peninsula in Southwest Asia. Yemen has an estimated population of more than 23 million people and is bordered by Saudi Arabia to the North, the Red Sea to the West, the Arabian Sea and Gulf of Aden to the South, and Oman to the east. Yemen's size is just under 530,000 km2, and its territory includes over 200 islands, the largest of which is Socotra, about 415 kilometres (259 miles) to the south of Yemen, off the coast of Somalia. Yemen is the only republic on the Arabian Peninsula. Its capital is Sana'a.