Weimar was important to the Nazis for two reasons: first, it was where the hated Weimar Republic was founded, and second, it had been a centre of German high culture during recent centuries. In 1926, the NSDAP held its party convention in Weimar. Adolf Hitler visited Weimar more than forty times prior to 1933. In 1930, Wilhelm Frick became minister for internal affairs and education in Thuringia, the first NSDAP minister in Germany. In 1932, the NSDAP came to power in Thuringia under Fritz Sauckel. In 1933, the first Nazi concentration camps were established around Weimar in Nohra (the first one in Germany) and Bad Sulza. Most prisoners at this time were communists and social democrats. After Kristallnacht in 1938, harassment of Jews became more intense, so that many of them emigrated or were arrested. The Weimar Synagogue was destroyed in 1938.