Sarmoung fortress hidden in the heart of Asia

"This old man", continued Bogga-Eddin, "is a member of a brotherhood, known among the dervishes by the name of Sarmoung, of which the chief monastery is somewhere in the heart of Asia."

...

I had several long conversations with this old man. In the last one he advised me to go to his monastery and stay there for a time.

...

He added that if I wished to go there, he would be willing to help me, and would find the necessary guides, on condition that I would take a solemn oath never to tell anyone where the monastery was situated.

...

Throughout the whole our journey, we strictly and conscientiously kept our oath not to look and not to try and find out where we were going and through what places we were passing. When we halted for the night, and occasionally by day when we ate in some secluded place, our bashliks were removed. But while on the way we were only twice permitted to uncover our eyes. The first time was on the eighth day, when we were about to cross a swinging bridge which one could neither cross on horseback nor walk over two abreast, but only in single file, and this it was impossible to do with eyes covered.

...

On the way we changed horses and asses several times, and sometimes went on foot. More than once we had to swim rivers and cross mountains, and by our sensations of heat and cold it was evident that we sometimes descended into deep valleys or climbed very high. At last, when at the end of the twelfth day our eyes were uncovered, we found ourselves in a narrow gorge through which flowed a small stream whose banks were covered with a rich vegetation.

...

As we came nearer we were able to make out something like a fortress such as one finds on a smaller scale on the banks of the Amu Darya or the Pyandzh. The buildings were encircled by a high unbroken wall.

Citation: 
pages 148-152