People used to enter Tillo, which is said to mean "rising souls" in Syriac language, with barefoot to pay tribute to the saints who live and lived there. Today, the madrasas still educate students in this city in which celestials resound in cobblestone pavements and it did not lose its mystic atmosphere.
The tomb of İsmail Fakirullah His Holiness who was an invaluable mudarris lived between 1655 and 1734; his student İsmail Hakkı His Holiness (1703-1780) and his grandson Sultan Memduh His Holiness (1761-1847) are in Siirt and are visited by tens of thousands of people every year.
Tomb of Zemzem-ül Hassa who was a female saint and poet, is also in Tillo. She was also the wife of Sultan Memduh. Tomb of Sheikh Hamza al-Kabir who lived in 13th century and the tomb of his son Sheikh İbrahim al-Mujahid are also in Tillo.
Scholar İbrahim Hakkı His Holiness, who calculated the distance between Earth and Moon as 43,198 parasangs in 1700s, also lived in Siirt. İbrahim Hakkı who was born in 1703 in Erzurum, made several inventions and important works of art under the guidance of his master İsmail Fakirullah His Holiness. He invented a staggering light mechanism for the tomb of his master by saying "What good could I expect from the sun that does not shine upon the gravestone of my master?"
On equinox days in which daytime and night-time are equal (21st of March and 23rd of September) the light from the sunrise illuminates the head part of the sarcophagus belongs to İsmail Fakirullah His Holiness through the end window of tomb.
İbrahim Hakkı His Holiness constructed a wall that is known as Kalet-ül Üstad, composed of stone settings, in order to establish this mechanism on a hill over the city. The sun light passes through the window of the tomb, and illuminates the head of the sarcophagus of İsmail Fakirullah His Holiness with the help of mirror reflections.
İbrahim Hakkı had a work of art called "Marifetname" composed of two volumes involving almost all science branches from geography to pedagogy, from psychology to sociology, from astronomy to criminology and from mathematics to biology. Cosmography tools, maps, spheres and manuscripts regarding sun systems that were used by him, are exhibited in İsmail Hakkı Hazretleri Museum that is a special museum in a house belonging to his grandchildren in Tillo.
Lord renders good all vice
Think not He does otherwise
The wise behold all moments
Shall we see what Lord does
Splendid is whatever He does