Architecture also fascinated the Dutch, churches in particular. At the start of the period the main tradition was of fanciful palaces and city views of invented Northern Mannerist architecture, which Flemish painting continued to develop, and in Holland was represented by Dirck van Delen. A greater realism began to appear and the exteriors and interiors of actual buildings were reproduced, though not always faithfully. During the century understanding of the proper rendering of perspective grew and were enthusiastically applied. Several artists specialized in church interiors.