In those cities the most important buildings were churches. They were commonly stone-built basilicas with three naves, three apses, columns, arches, arcades and wooden roofs, and were erected near the monasteries of Benedictine monks who came out of Italy. St. Peter in "Supetarska Draga" on the island of Rab (11th century) is the best-preserved church of that type in Croatia. On the same island is the "Cathedral of Rab" (12th century) that has a high-Romanesque bell tower, the largest in Dalmatia. It is specific with its openings, which multiply with each level of floor (Latin: mono-fore, bi-fore, tri-fore, quadro-fore). This is typical for Romanesque architecture, but also architecturally innovative, as each floor is slightly lighter than the one below.