In northwestern Croatia, the beginning of the wars with the Ottoman Empire caused many problems but in the long term it both reinforced the northern influence by establishing the Austrians as the rulers of a large part of Croatia. With permanent danger from the Ottomans in the east, there was only a modest influence of the Renaissance, while fortifications thrived. The plan for the fortified city of Karlovac in 1579 was the first entirely new urban city to be built by Renaissance plans (so called "ideal city" plan) in Europe. It was built in radial plan, later common in Baroque city design. The Renaissance fort of the Ratkay family in "Veliki Tabor" from the 16th century has mixed features of Gothic architecture (high roofs) and Renaissance (cluster and round towers) making it an example of Mannerism.