Seiyun Palace or Kathiri Palace, one of the largest and rarest palaces built of mud bricks more than 5 centuries ago in the city of Seiyun in Hadramout (southeast Yemen), and it was affiliated with the Kathiri state whose sultans successively renewed its architecture and added new facilities, accessories and outlets, throughout their rule from 1411 to 1967. The palace, which took 15 years to build on an area of 5,460 square meters, is characterized by unique and consistent architectural creativity, and is considered an archaeological engineering masterpiece and one of the most important heritage landmarks in Yemen. In 1984, it became the headquarters of the General Authority for Antiquities and Museums, and the headquarters of the Seiyun Museum. It was the face of a thousand riyals coin. The palace consists of 4 corners, and it has 4 entrances on each side, an official entrance, and in the front two entrances. The building, consisting of 6 floors, was built in 1926, and its height exceeds 25 meters, and its height relative to the ground level is more than 45 meters. The palace knew different patterns in its construction, as every sultan used to add and put his mark in the place, as the palace was basically built as a fortress, so the building was based on fortifications that included the wall and other facilities, and when it turned into a palace, its upper floors were added. It was like a gigantic mud castle with towers in its corners, and the height of its building revealed all the city and the neighboring villages. It also provided elements for confronting the siege, such as watch towers, large warehouses, and a water well, and this was proven in many battles that the city witnessed. A palace made of adobe clay The process of building the geometrically symmetrical Seiyun Palace was carried out in several successive stages of time, and the character of its mud construction was gradual. The building was made of mud and adobe, and it was left at each stage until the moisture dried from it and its salts were excreted after exposure to the wind and the sun, then it was coated with lime from the outside. Its white color had an important role in reflecting the sun's rays on the building, which reduces the heat it absorbed throughout that period. With this mud architecture, the palace was erected and was ultimately coherent, symmetrical and beautiful, and has remained steadfast until today, as it has known since its establishment two stages of restoration, the first in 1516 and the second in 2001, and archaeologists confirm that it cannot withstand without continuous restoration and maintenance. Mud architecture flourishes in Wadi Hadramout, due to its suitability to the valley's atmosphere, which is characterized by heat and dryness. Studies have shown a clear harmony between the spatial environment represented by the natural environment of all kinds, and the mud building architecture in the region. The palace is still in its condition until now, and more than 50% of its area has become a museum, which opened in 1983, and its halls include archaeological collections of historical value, including: Ancient antiquities collected from separate sites of Wadi Hadramout. The antiquities that were extracted from the excavations of the archaeological site of Ripon, and other areas in the valley, and represent different stages in the history of the region, and are the result of the excavations of Russian, French, Yemeni, British surveys and various missions. Antiquities and inscriptions dating back to the era of the ancient Yemeni kingdoms. Antiquities dating back to the Islamic era, including wooden mosque pulpits, the oldest of which dates back to 1274 AD. The popular heritage that the city of Hadramout abounds. The ancient documents of the many states that took Seiyun as their capital in one of its late periods, which are the flag of the state and its official documents such as passports, various licenses, coins, types of weapons, and others. More information https://en.m.wikipedia.org/wiki/Seiyun_Palace https://www.bbc.co.uk/news/world-middle-east-54599906 https://www.aljazeera.com/news/2020/10/16/mud-brick-palace-is-yemens-latest-heritage-site-facing-disaster