On the picture: some of the buildings of the ‘Tekke’ (or ‘dergah’), on the north side of the lower courtyard.
They were built in 1511.
From right to left: The door of the ‘fırın’ (bakery), and the two large rooms of the Semahane. The latter were used for the ritual gatherings of the dervishes. ‘Semahane’ means ‘House of the Semah’, Semah being the ritual dance performed by the Bektaşi and Alevi. The left Semahane room is called ‘Kırklar Meydanı’ (Gathering of the Forty Witnesses), a terminology exclusively used by Bektaşi and Alevi.

Regarding the Bektaşi Order:
This is an Islamic Sufi order (‘tariqat’) named after the 13th century Alevi Saint Hacı Bektaş Veli, but founded by Balım Sultan in the early 16th century. In addition to the spiritual teachings of Hacı Bektaş Veli, the Bektaşi Order was later significantly influenced during its formative period by Shia beliefs circulating in Anatolia (14th – 15th century). Balım Sultan systematized and structured the mystical practices and rituals of the Order, fusing a number of Shia and Sufi concepts, which resulted in a wide appeal and influence among both the Ottoman intellectual elite as well as the peasantry. The order had in particular close ties with the Janissary corps, the elite infantry troops of the Ottoman Army.

The Bektaşi Order shares much in common with other Islamic mystical movements, such as the need for an experienced spiritual guide — called a ‘baba’ (= father) in Bektaşi parlance — as well as the doctrine of ‘the four gates that must be traversed’: the ‘Sharia‘ (religious law), ‘Tariqah‘ (the spiritual path), ‘Marifa‘ (true knowledge) and ‘Haqiqah‘ (truth).
Bektaşism places much emphasis on the concept of the ‘Unity of Being’ (which has often been labeled as pantheism). It is also heavily permeated with Shiite concepts, such as the marked veneration of Ali, The Twelve Imams, and the ritual commemoration of Aşurah marking the Battle of Karbala.

The order is mainly found throughout Anatolia and the Southern Balkans. Because of the shared spiritual base (the teachings of Hacı Bektaş Veli) and some common rituals, the Bektaşi Order nowadays is very close to the Anatolian ‘Alevi’ (which is not an Order, but a people’s movement based on religion).

Correspondent: J.M.Criel, Antwerpen.
Sources: Leaflet of the Seyitgazi Külliyesi (1995) , Wikipedia & Personal visits (1995 – 1996).