NIKOLSBURG (Czech, Mikulov), a town of Austria, in Moravia, 53 m. S. of Brünn by rail. Pop. (1900) 8091. It is situated at the foot of the Polau Mountains and near the border of Lower Austria. It possesses a château of Prince Dietrichstein-Mensdorff, which contains an extensive library, with some valuable manuscripts. The Heiliger Berg, in the immediate vicinity, has sixteen chapels, and a church in the Byzantine style. The principal resources are viticulture, the manufacture of cloth, and trade in lime and limestone. On the 31st of December 1621 peace was concluded here between the emperor Ferdinand II. and Bethlen Gabor, prince of Transylvania; and on the 26th of July 1866 a preliminary treaty of peace between the Prussians and the Austrians was signed here.