 The building's exterior is dominated by heavy flying buttresses which allowed the architects to increase the window size significantly, while the west end is dominated by two contrasting spires – a 105-metre (349 ft) plain pyramid completed around 1160 and a 113-metre (377 ft) early 16th-century Flamboyant spire on top of an older tower.Equally notable are the three great façades, each adorned with hundreds of sculpted figures illustrating key theological themes and narratives.Since at least the 12th century the cathedral has been an important destination for travellers.