An 18th-century palace used hollow walls and floor ducts to circulate hot air from central furnaces. The passive heating system distributed warmth via convection currents, achieving uniform temperature control without pumps or fans.
Volcanicaa, CC BY-SA 4.0, via Wikimedia Commons
A palace of blended styles
Set on a rocky platform 5 kilometers from Doğubeyazıt, the Ishak Pasha Palace overlooks the plains from an elevation of 2,000 meters. Its construction began in 1685 under Çolak Abdi Pasha and was completed in 1784 by his descendant, Ishak Pasha II. The complex, measuring approximately 115 by 50 meters, is a large-scale administrative palace from the late Ottoman Empire. The architecture is not purely Ottoman; it combines elements from Persian, Seljuk, and even European Baroque traditions.
The palace is organized around two main courtyards and contains 366 rooms, including a mosque, a kitchen, baths (hammam), dungeons, and extensive harem and selamlık (men's quarters) sections. Cut stone from the surrounding area was used for its construction. This remote structure functioned as a small city, complete with amenities that were exceptionally advanced for its time, including running water and a sewerage system.
The science of passive heat
The most scientific feature of Ishak Pasha Palace is its central heating system, an application of thermodynamics. The system operates on the principle of natural convection. Furnaces located in the basement heated air. This hot air, having a lower density than the surrounding cooler air, would naturally rise.
A network of hollow channels and terracotta pipes (earthed pipes) was integrated within the stone walls and beneath the floors of the palace. As the hot air ascended from the furnaces, it flowed through this extensive network. The heat transferred from the air through the terracotta and stone, warming the surfaces of the rooms. As the air cooled, its density increased, causing it to sink and circulate back down to the furnaces to be reheated. This process created a continuous, self-sustaining loop that distributed warmth throughout the main living quarters without any mechanical pumps or fans. This method of underfloor and in-wall heating is conceptually similar to the hypocaust systems used by the Romans, but its implementation in the 18th century is a feat of engineering.
💡Fun Facts
The palace is considered the second most important administrative campus of its era, after the Topkapi Palace in Istanbul.
The original gilded wooden gates of the palace were taken during the 19th century and are now on display at the Hermitage Museum in St. Petersburg, Russia.
The palace once appeared on the reverse of the Turkish 100 new lira banknote, used from 2005 to 2009.
In addition to central heating, the palace had a running water supply and a sewage system.
Summer (April-October): 09:00-19:00; Winter (November-March): 09:00-17:00. The palace is closed on Mondays. Ticket counters close 15-30 minutes before the palace.
Admission
The admission fee is €3.00 for adults.
Accessibility
The palace is situated on a steep hill with uneven, rocky ground. Its historical structure includes multiple levels and courtyards which may present challenges for visitors with mobility issues.
