Denizli

i.The Çürüksu (Lycus) Valley and the Travertine Cliffs

Denizli sits in the wide upper valley of the Çürüksu — the river the ancient Greek geographers called the Lycus, "the Wolf" — at the meeting of the Aegean coastal country and the high Anatolian plateau. The valley runs roughly east-west between two long mountain walls: the Honaz Dağı (2,571 m) and the rest of the Mendere ridge to the south, and the Babadağ ridge to the north, with the small parallel river Menderes (the ancient Maeander) running west fifteen kilometres beyond. The country between the two rivers is a fertile plain — vineyards, olive groves, cotton fields — and it was, for fifteen centuries, the most prosperous corner of inland Aegean Asia Minor.

The geological signature of the province is the travertine cliff at Pamukkale — "the Cotton Castle" — where calcite-laden hot springs rising in the cliff face have, over millennia, deposited a vast cascade of brilliant white limestone terraces and pools that runs almost two hundred metres down the rock face. The terraces are still active; the springs still flow. The visual effect — a wall of cotton-white stone catching the late-afternoon sun against the brown plain — is among the most distinctive landscapes in Türkiye and the visual basis of the UNESCO mixed-property inscription.

ii.Hierapolis — the Attalid Thermal City

The city the Greeks called Hierapolis — "the holy city" — was founded at the head of the travertine cliffs in the late 2nd century BCE by the kings of Pergamon (the Attalid dynasty, see our forthcoming Pergamon essay) as a thermal spa exploiting the hot springs. The foundation was probably by Eumenes II around 190–160 BCE. After 133 BCE the city passed with the rest of the Pergamene kingdom to the Roman Republic and was incorporated into the new province of Asia.

Roman Hierapolis grew rapidly to become one of the great spa-and-textile cities of the eastern Mediterranean. The city's wealth rested on three things: the thermal baths, into which patients came from across the empire; the wool of the surrounding plain, which the Hierapolitans dyed using the famous local cardinalis red and exported across the Mediterranean; and the city's strategic position on the trans-Anatolian road from Ephesus to the eastern frontier. The 4th-century theatre — restored under Septimius Severus and again under Constantine — held twelve thousand spectators and is now the most spectacular standing structure of the site. The Roman gate (the Frontinus Gate, 86 CE) and the great Necropolis — over a thousand surviving tombs and sarcophagi — run for two kilometres along the road north of the city.

iii.Laodicea on the Lycus

Six kilometres north of modern Denizli, on the south bank of the Lycus, lay Laodicea on the Lycus — the Seleucid foundation of Antiochus II Theos, sometime between 261 and 263 BCE, named for his wife Laodike. Laodicea was a Hellenistic-Roman city of great size — at its 1st-century-BCE peak the population is estimated at 100,000 to 150,000 — and one of the principal commercial cities of inland Asia. Strabo describes it as "one of the most prosperous in Asia."

The city's economy was built on the surrounding fertile plain, on its position at the meeting of the trans-Anatolian road and the road south to Lycia, and on the famous "glaucus" black wool of the local sheep — a wool so dark it was used to make the imperial-purple-edged toga of the Roman senatorial class without further dyeing. Laodicea was also the major medical centre of inland Asia, with a school of medicine attached to the temple of Mên (the Phrygian moon-god). The city's wealth is referenced ironically in the New Testament — Laodicea is the seventh and last of the Seven Churches of Asia addressed in the Book of Revelation (Revelation 3:14–22), whose author rebukes the Laodicean Christians for being "lukewarm — neither hot nor cold" and "rich, increased with goods, and have need of nothing."

iv.Roman and Byzantine Centuries — the Earthquakes

The Lycus valley sits on an active seismic zone, and the cities of the valley were repeatedly destroyed and rebuilt across the Roman and Byzantine centuries. Major earthquakes are recorded in 17 CE under Tiberius (when the Roman senate granted Sardis, Hierapolis, and a dozen other Asian cities a five-year tax remission for rebuilding) and in 60 CE under Nero (the destruction that the Roman historian Tacitus describes, after which the city refused imperial aid and rebuilt at its own expense — the moment Pliny the Elder calls Laodicea's most famous). The catastrophic earthquakes of 602–610 CE during the reign of the emperor Phocas ended ancient Laodicea: the city's inhabitants moved a few kilometres south to the more defensible hilltop site at Kaleiçi / Hisarköy — the kernel of the modern Denizli — and Laodicea proper was permanently abandoned.

Hierapolis fared better. The city continued through the Byzantine centuries as an active episcopal seat and the home of a substantial Christian community — its bishop ranked among the most senior of the Asian metropolitans — but progressively contracted from the great Roman city to a small fortified mediaeval town.

v.Saint Philip and the Christian Centuries

The most consequential Christian episode in the city's history is the martyrdom of Saint Philip, one of the twelve apostles, who is said in early-Christian tradition to have been killed at Hierapolis around 80 CE, in the persecution under Domitian. The Martyrium of Saint Philip — a great octagonal monument built in the 5th century in commemoration on the hillside above the city — was excavated by the Italian Archaeological Mission in 1957–82; the adjacent tomb of Saint Philip was identified by Francesco D'Andria in 2011 as a small 1st-century mausoleum at the centre of the complex. The Saint Philip cult drew pilgrims from across the eastern Mediterranean through the Byzantine centuries.

vi.The Seljuk and Beylik Periods

The Turkish arrival on the Lycus came in the late 11th century, after the Battle of Manzikert. Hierapolis itself passed to the Anatolian Seljuk Sultanate of Rûm in the late 12th century — the Valilik dates the transition broadly to "the end of the 12th century." Through the 13th century the country was held by the Seljuks and then, after the post-Mongol fragmentation, by the small Turkmen Beylik of İnançoğulları, which had its capital at the small new town of Tonguzlu — the medieval ancestor of modern Denizli, three kilometres south of the abandoned site of Laodicea. The town's name shifted through Tonguzlu → Denizli over the next two centuries.

The İnançoğulları were absorbed by the larger Germiyanoğulları beylik in the 14th century, and the Denizli country was held by the Germiyanid dynasty until the early 15th century.

vii.Ottoman Denizli (1428 onwards)

The Ottoman annexation came in 1428, when Sultan Murad II incorporated the last of the Germiyanid territories into the Anatolian sancak. Denizli was made a working sancak centre, and through the long Ottoman centuries served as the principal market town of the upper Maeander-Lycus country. The Ottoman period gave the town its modern urban form — the central Bayramyeri Camii (1492), the small Akhan (Ak Han) caravanserai south of the town, and the Çamlık Camii are the principal Ottoman monuments. The town was almost entirely rebuilt after the catastrophic 1899 earthquake, which destroyed most of the late-Ottoman fabric; the modern grid plan of central Denizli dates from the 1900s.

viii.UNESCO 1988 — Hierapolis-Pamukkale

In 1988, UNESCO inscribed Hierapolis-Pamukkale on the World Heritage List as a mixed (cultural and natural) property under cultural criteria (iii) and (iv) and natural criterion (vii). The inscription rationale identifies the property's "Outstanding Universal Value" as resting on the strong integration between the natural landscape (the travertine terraces and the active thermal springs) and the cultural fabric (the Greco-Roman and Byzantine city above and beside the cliffs). The site's principal monuments — the Roman theatre, the necropolis, the Frontinus Gate and the colonnaded street, the Martyrium of Saint Philip, and the so-called Plutonium (the carbon-dioxide-emitting cave that the ancients identified as a gate to the underworld) — are all preserved within the inscription boundary.

The 1990s and 2000s saw substantial conservation work at the site, including the removal of the post-war hotels that had been built on top of the travertine terraces, the restoration of the thermal-pool circulation system, and the reconstitution of large parts of the theatre. The site is administered by the Pamukkale Site Management Directorate under the Ministry of Culture and Tourism.

ix.The Republic and the Modern Textile City

Republican Denizli grew steadily through the 20th century. The transformation into a major industrial centre came in the post-1980 period, with the rapid expansion of the city's cotton textile industry — initially household-textile manufacture (towels, bathrobes, bed linens) for the European export market, later expanding into denim, ready-to-wear, and synthetic blends. Today, Denizli is the principal towel-and-bathrobe production centre in Türkiye and one of the principal textile-exporting cities of the country.

Under the TÜİK 2024 address-based registration count the province population was 1,061,371. The metropolitan municipality covers nineteen districts. The two central districts of Merkezefendi (~346,000) and Pamukkale (~346,000) carry over two-thirds of the metropolitan population between them. The smaller districts of Çivril (~60,000) and Acıpayam (~55,000) are the principal rural-and-agricultural districts. The province is the seat of Pamukkale Üniversitesi (founded 1992).

x.What to See, in Order

The walking circuit of the UNESCO property begins at the upper entrance, at the head of the travertine cliff. The visitor walks barefoot down the travertine terraces themselves — the only way visitors are now permitted to descend, and the only way to preserve the active calcification of the pools — through the lower terraced basins to the modern Pamukkale village at the foot of the cliff. The upper site of Hierapolis — entering through the South Gate — includes the great Roman theatre, the Necropolis running northwest from the city walls, the Frontinus Gate with its colonnaded street, the Plutonium, and on the upper hillside the Martyrium of Saint Philip with the recently identified tomb at its centre. The on-site Hierapolis Müzesi — housed in the restored Roman baths — holds the principal moveable finds.

South of the modern city, the site of Laodicea — long neglected after the 7th-century abandonment, now under continuous excavation since 2003 by a Turkish team under Celal Şimşek — covers about five square kilometres on its open plateau, with the great Stadium (still partly buried), the South Bath complex, the so-called Syrian Temple, the colonnaded streets, and the late-antique churches that mark the city of the Book of Revelation. Further afield, the small site of Tripolis (Yenicekent) and the medieval caravanserai of Akhan on the Ankara road are the natural day-excursions.

The Lycus valley — Pamukkale's white cliff above, the Attalid thermal city of Hierapolis, and the great Hellenistic and Roman Laodicea below.

For the parallel Aegean province to the west, see Muğla; for the great Pergamene capital that founded Hierapolis, see the planned Pergamon essay. For the Maeander-valley parallel, see Aydın. For Türkiye's Aegean coast in the wider sense, visit our sister site CountryOfTurkey.com.