Ali Yamaç is a Turkish speleologist. He was born in 1957 and has been caving since 1976. During these years he has surveyed and explored hundreds of caves, some of which are the longest and deepest caves in Turkey. He was the president of the Speleological Federation of Turkey in 2007-2009 and the president during the foundation of three different speleological organisations. He was the leader of the team that prepared the cave inventory of Turkey. In addition to his natural cave explorations, he has explored and surveyed numerous rock dwellings and underground cities in different regions of Turkey as part of his artificial cave projects. Beginning with surveys of the underground structures of Hagia Sophia and Topkapi Palace in Istanbul, his artificial cave projects continue with underground structure inventory projects in the provinces of Kayseri and Gaziantep. Both projects have been underway for more than ten years and both have been accepted to the UNESCO World Heritage Tentative List. At the request of the directors of the Nevşehir and Aksaray Archaeological Museums, he has surveyed the underground shelters of Derinkuyu, Mazıkoy, Mazıkoy 2, Tatlarin, Avanos, Golgoli and St. Mercurius; he has also investigated rock-cut settlements and churches on the Euphrates River cliffs as part of the Euphrates River Cliff Settlements Project; and he has surveyed several settlements as part of the Kura River – Ardahan Region Survey. In 2025, he had started ‘Ürgüp Underground Structures Inventory Project’. He has previously published “Caves and Karst of Turkey”, “Caves and Karst of Küre Mountains National Park”, “Rock-cut Architecture and Underground Cities in Koramaz Valley of Kayseri, Turkey” and “Underground Shelters of Cappadocia, Turkey”.