The Underground Water Structures in Gaziantep; Livas and Kastels Gaziantep, situated on the banks of the Alleben Stream, has been inhabited since the late 5th century. Despite the C-shaped settlements that the stream runs through, it's prone to running low on water during summers. Due to the limited water supply, the city's development required the use of waterways. Gaziantep's ancient water system is composed of underground tunnels called livas, which transport groundwater from distant sources to the city, as well as water structures called kastels, which distribute the water flowing from these tunnels for various purposes. Livas are constructed by human excavation of the limestone rock on which the city was built. The concept of livas is based on transporting water from an external source to the heart of the city via underground tunnels and distributing it to major cities via carefully sloping underground tunnels, where it's then delivered to water structures at designated locations. With the city's expansion, additional tunnels were dug to meet the growing demand for water. This resulted in a "system of livas" that stretches for miles, encircling the city like a spiderweb. Gaziantep's water system includes a network of subterranean tunnels called livas, which bring groundwater from a distant source to the city, and kastels, buildings where the water from the livas is made available to the public. The Pancarlı Livas Line is the oldest livas line, transporting water from about 14 kilometers northwest of the city. While the origin and duration of construction of the system are unknown, it is evident that the system has expanded over time alongside the city. Kastels, on the other hand, were built at various depths depending on the height of the livas' lines. These architecturally magnificent structures have evolved over time, with the oldest being fully below-ground and others partly below-ground. They include many functions in their spatial designs, such as pools, wells, seating areas, tiny mosques, water closets, and swimming spots. Kastels also serve as an important meeting place in the city's social life, where people gather, conduct business, and practice religious worship. They were also used to keep the public cool on hot summer days. Today, only six kastels have survived: Kastel of Pişirici (Beşinci), Kastel of İhsan Bey (Esenbek), Kastel of Şeyh Fethullah, Kastel of Kozluca, Kastel of Ahmet Çelebi and Kastel of İmam Gazali. Many of these livas and kastels date back to the 12th and 13th centuries and have been listed in the Tentative List of UNESCO in 2018.