Ghumdan Palace, also Qasir Ghumdan or Ghamdan Palace, is an ancient palace and fortress in Sana'a, Yemen. It is the earliest known castle in the world. All that remains of the ancient site of Ghumdan is a field of tangled ruins opposite the first and second of the eastern doors of the Jami‘ Al Kabeer Mosque. This part of Sana'a forms an eminence which is known to contain the debris of ancient times. The place is located on the extreme southeastern end of Sana'a's old walled city, al-Qaṣr, just west of where the Great Mosque of Sana'a was later built, and is part of the UNESCO World Heritage Site of the Old City of Sana'a. It is sometimes referred to as Ghumdan Tower.

Sanaa, also spelled Sana'a and Sana, is the capital and largest city of Yemen and the capital of the Sanaa Governorate. The city is not part of the Governorate but forms the separate administrative district of ʾAmānat al-ʿĀṣimah. According to the Yemeni constitution, Sanaa is the capital of the country, although the seat of the Yemeni government moved to Aden, the former capital of South Yemen, in the aftermath of the Houthi occupation. Aden was declared as the temporary capital by then-president Abdrabbuh Mansur Hadi in March 2015.