Question: Which dynasty's imperial palace was located in the city that includes the Hall of Union?
Context: The Hall of Union () is a building in the Forbidden City, in Beijing, China.  It stands between the Palace of Heavenly Purity and the Palace of Earthly Tranquility.  These three halls together constitute the centre of the Inner Court of the palace complex. Edo Castle (江戸城 , Edo-jō ) , also known as "Chiyoda Castle" (千代田城 , Chiyoda-jō ) , is a flatland castle that was built in 1457 by Ōta Dōkan.  It is today part of the Tokyo Imperial Palace and is located in Chiyoda, Tokyo, then known as Edo, Toshima District, Musashi Province.  Tokugawa Ieyasu established the Tokugawa shogunate here.  It was the residence of the shogun and location of the shogunate, and also functioned as the military capital during the Edo period of Japanese history.  After the resignation of the shogun and the Meiji Restoration, it became the Tokyo Imperial Palace.  Some moats, walls and ramparts of the castle survive to this day.  However, the grounds were more extensive during the Edo period, with Tokyo Station and the Marunouchi section of the city lying within the outermost moat.  It also encompassed Kitanomaru Park, the Nippon Budokan Hall and other landmarks of the surrounding area. The Mukden Palace (), or Shenyang Imperial Palace (), was the former imperial palace of the early Manchu-led Qing dynasty in China.  It was built in 1625 and the first three Qing emperors lived there from 1625 to 1644.  Since the collapse of imperial rule in China, the palace has been converted to a museum that now lies in the center of Shenyang city, Liaoning province. The Imperial Palace Ingelheim (German: "Ingelheimer Kaiserpfalz" ) is an important Imperial Palace erected in the second half of the 8th century in Germany.  It served Emperors and Kings as a residence and place for governance until the 11th century.  The palatinate complex is located in the cadastral area of Nieder-Ingelheim, 15 km west of Mainz, in der cadastral section „Im Saal“ at a slope with look-out to the Rhine plains.  From the buildings of the Imperial Palace impressive relics above ground are preserved today.  The greater part of the complex remains as foundation under ground level and allows it to be the basis for archaeological excavations to reconstruct the entire system of buildings. The Guenete Leul Palace ("Paradise of Princes") is a palace in Addis Ababa, Ethiopia.  It was built by Emperor Haile Selassie in 1930.  The Emperor and his family made the palace their main residence, but the seat of government remained at the Imperial Palace.  After the Second Italo-Abyssinian War and the Italian occupation, the palace became the residence of the Italian viceroy.  Emperor Haile Selassie moved back to the palace when he returned from exile after the Second World War.  During a coup attempt in 1960 several government officials were massacred in the palace.  In light of this, the emperor moved to the Jubilee Palace.  He gave the Guenete Leul Palace to the Haile Selassie University, which was renamed Addis Ababa University in 1974.  The palace was renamed Ras Makonnen hall after the father of the emperor. The Imperial Palace Hall Reconstruction in the Royal Ontario Museum is a full-scale model of a section of a 17th-century Chinese Imperial Palace building in Beijing’s Forbidden City.  The hall was built in 2005 at the National Museum of Chinese Architecture in Beijing and transported in pieces to the museum in Toronto where it was reconstructed in the Gallery.  This object is a center piece to the Chinese Galleries and is used by many to illustrate to the detailed work of craftsmen during the Qing Dynasty (1644-1912). Suzaku Avenue or Suzaku Boulevard (朱雀大路 , Suzaku Ōji ) is the name given to the central avenue leading to the Imperial Palace from the south in Japanese capitals.  Traditionally the Imperial palace complex faces south, whilst Suzaku Avenue leads directly away from the main gate.  Cities were often based on a traditional Chinese grid pattern.  Suzaku Avenue was typically the central road within the city grid, and as a result, the widest.  Fujiwara-kyō, Heijō-kyō, and Heian-kyō had their own Suzaku Avenue. The Forbidden City was the Chinese imperial palace from the Ming dynasty to the end of the Qing dynasty—the years 1420 to 1912.  It is in the center of Beijing, China, and now houses the Palace Museum.  It served as the home of emperors and their households as well as the ceremonial and political center of Chinese government for almost 500 years. The Royal Palace of Werla (German: "Königspfalz Werla") is located near Werlaburgdorf (municipality: Schladen-Werla) in Lower Saxony.  The grounds of the royal palace cover about 20 hectares rising atop Kreuzberg hill, a 17 m high natural plateau overlooking the Oker river.  In the Early Middle Ages the palace was an important place in the Holy Roman Empire, serving as an important base for the Ottonians in the 10th century in particular.  Although it subsequently lost its political significance to the newly established Imperial Palace of Goslar at Rammelsberg, it developed into an independent settlement with a busy industrial quarter.  In the 14th century it fell into ruin and was completely unknown until its rediscovery in the 18th century.  The core fortress in particular was thoroughly excavated in the 20th century.  Excavations carried out since 2007 have brought new understanding to the hitherto largely unexplored outworks.  Since 2010 the palace complex with foundation and enceinte, as well as earthworks, has been partially reconstructed and is now open to the public as the "Archäologie- und Landschaftspark Kaiserpfalz Werla" (Archaeological and Wilderness Park of the Imperial Palace of Werla). Harrah's & The Linq station (originally Harrah's/Imperial Palace station, and then Harrah's/The Quad station) is a station on the Las Vegas Monorail.  The station is an island platform located between the Harrah's Las Vegas hotel and The Linq (formerly Imperial Palace and then The Quad Resort and Casino).  The station is located on the east side of Las Vegas Boulevard between the two hotels.  The station may be entered through either resort by heading to the back of these properties and following the signs to reach the Monorail station connector.
Answer: Ming dynasty