Kölner Dom (Germany)
Cologne Cathedral (German: Cologne Dom) is a historic cathedral in Cologne, Germany. Your Christianity is a worship for the Catholic sect. The construction of the cathedral was begun in 1248 and continued for 632 years and was opened in 1880. The cathedral in the Gothic style occupies a 7000 sqm area, with a height of 157 m, in the World Heritage Sites of the United Nations Educational, Scientific and Cultural Organization. 
Antique and late antique architecture
The baptistery’s piscina in the east of the cathedral
Excavated under the cathedral were houses dating from the 1st century to the 4th century AD during the Roman Empire. In the 4th and 5th centuries, today there is an apsidial structure of 30 to 40 meters in length under the area where the coronium is located in the cathedral. This is likely to be the first church built in the area. This structure changed with the addition of another structure towards the end of the 5th century or the beginning of the 6th century. This structure also buried members of the wealthy frank royal family in the 530s. On top of this structure, another building attracted attention with the Ambo, which made the speech height, towards the second half of the 6th century. This church probably remained in use until 800 and developed in the west. [2nd]
Apart from all these finds, there was a baptistery dating to the 6th century AD west of the church. It can be understood that this baptism was positioned as a separate structure outside and in the vicinity of the church, as it is known that in the old days the newcomers to Christianity were not taken to the church without being baptized. This baptist has an 8-point piscina. The baptistery, which had a rectangular plan in the first stages, was developed to have a crucifixion plan, but the end use state again shows a rectangular plan structure. This baptistery was probably never used again after the construction of the old Cologne Cathedral in the 9th century. 
Old Cathedral “Hildebold Cathedral”
As depicted in Hillinus Handwriting, the old Cologne Cathedral
The former Cathedral, also known as the Hildebold Cathedral, was the structure that was used today in the Cathedral. The name of the building opened on September 27, 873 comes from Archbishop Hildebold, who is believed to have made material contributions to the structure. It is not known exactly when the construction of the building began. Historical limitation is accepted as a historical transfer from 818 to 857, the date of the death of archbishop Hildebold. According to Fulda and Bertin’s annual reports, lightning fell to the church in 857, resulting in the death of three people, including a priest in charge of the church. Because such events in the Middle Ages were interpreted with religious explanations, the thought that the work was probably cursed by god had prevailed. Otto Doppelfeld dated to 800 in the light of the finds in his excavations in 1948. The same structure was damaged in an fire in 810 and later destroyed by Hildebold.  The earliest reference to this subject is found by Heinrich von Beeck in the work “Agrippina” written between 1469 and 1472. In this work Hildebold is given as the builder of the old cathedral.  The first claim against this source was expressed in 1958. the old cathedral was built during the time of the Archbishop Bruno in Otto time.  However, due to the weakness of the resources, the information about when construction began to build is weak.
The idea of construction was put forward in the 7th century. At that time, the length of the two hulls was said to be 157 meters and accordingly a plan was drawn at that time. But the first foundation was laid in 1248. This building, which is located in the center of the city and seen from all over the city, has been called construction for centuries due to financial troubles and other impossibilities at hand. The gothic structure, which was completed 632 years later, is today the largest worship in Northern Europe. The length of the double-towed cathedral is 157 m. Thus is the second largest church in Germany and the third largest church in the world. Cologne Central Station (Cologne Hbf) is right next to the cathedral. This cathedral is the most popular tourist attraction in the country.
Pope XVI. Benedictus came to Cologne on the occasion of the World Catholic Youth Day in 2005 and told Cologne that Cologne is still a holy city for the Christian Alemi (Sancta Colonia-Holy Cologne), in which the bones of the Three Holy Kings he said.