Stone was for a long time used only for columns, capitals, window frames|, doorways, balustrades| and decorative details, such as cornices, inlaid medallions and reliefs. It was only in the 15th century that the first facades entirely in stone| appeared. The most widely used stone was a limestone from Istria, a peninsula which was part of the territories of the Republic and was easily accessible by sea. Resembling marble, Istrian stone is hard, resistant to weathering, and relatively easy to carve. Its combination with brick, and the resulting colour scheme, defines the image of a vast proportion of Venetian architecture.