The Basilica of York, also known as St. Peter's Basilica, is the largest in the UK and the largest Gothic church in the entire European Alps, which began construction in 1220 and was completed in the 1470s. Entering York Cathedral, the most amazing is the back of the altar, a whole piece of stained glass on the east side of the church, the area is almost the size of a tennis court, is the largest medieval stained glass window in the world, the eastern stained glass window was designed between 1405 and 1408 AD, It is composed of more than 100 pictures, fully showing the wonderful process of staining, cutting and combining glass during the Middle Ages, and the architectural power of supporting the eastern walls with large glass glaze is also breathtaking.