Until a few years ago the architecture of the Turkish derwish orders of the classical period of Ottoman architecture was unknown. In 1967 the profound and richly illustrated study by Prof. Semavi Eyicei of the Tekke of Akyazıh Sultan in North-East Bulgaria appeared, whereby the importance of this long-known but never understood monument was convincedly demonstated and its place located in classical Ottoman architecture. Of great importance is its reconstruction and an explanation of the function of the monumental edifice next to the Turbe of the Saint, i.e. the Asitane, the spacious hall in which the derwishes held their meetings. This hall of which the walls have remained up to the adjoint piece of the truss, is a rare type of Ottoman architecture of which it was the only known specimen. The architectural heritage of the Osmanlı in the Balkans is for the most part little known, if at all. Thus, Bulgaria, Greece and also the Yugoslavian state of Makedonia stili hold unknown treasures in the field of architecture. Only the Bosnian Moslems and the Hungarians have performed meritorious work on a large scale, thanks to which we are better informed about these areas. While making a journey of 16000 km through the former provinces of the Ottoman Empire in Europe in the summer of 1969. I was afforded the opportunity of visiting and describing several monuments unknown to science. One of these objects is the second example of a heptagonal 'Asitane belonging to the classical period of Ottoman architecture.