Many churches were built along pilgrimage routes. A number in Europe were either founded or rebuilt specifically to enshrine relics, (such as San Marco in Venice) and to welcome and awe the large crowds of pilgrims who came to seek their help. Romanesque buildings developed passageways behind the altar to allow for the creation of several smaller chapels designed to house relics. From the exterior, this collection of small rooms is seen as a cluster of delicate, curved roofs at one end of the church, a distinctive feature of many Romanesque churches. Gothic churches featured lofty, recessed porches which provided space for statuary and the display of relics.