I haven’t been here (yet).
Built in the 12th and 13th centuries, this was Scandinavia's first Gothic cathedral to be built of brick and it encouraged the spread of this style throughout northern Europe. It has been the mausoleum of the Danish royal family since the 15th century. Porches and side chapels were added up to the end of the 19th century. Thus it provides a clear overview of the development of European religious architecture. [source]