The calcium-rich thermal springs at Pamukkale have been depositing brilliant white travertine for seventeen thousand years, creating terraced pools that spill down a hundred-metre slope above the Denizli plain. The site earned UNESCO World Heritage status in 1988, protecting both the mineral formations and the sprawling ruins of Hierapolis, the Greco-Roman spa city built directly above the springs in 190 BCE. Today the Cotton Castle — pamukkale in Turkish — welcomes visitors who remove their shoes and wade through the shallow thermal pools, following boardwalks that preserve the fragile carbonate crust. A Marmaris Pamukkale tour covers the two-hundred-seventy-kilometre route inland from the Aegean coast, crossing the Menderes valley and climbing into the highlands of southwestern Anatolia. Most full-day excursions depart Marmaris before dawn, reaching the travertines by mid-morning when the white terraces catch the low sun and the site remains quiet. The journey includes a scheduled stop at Hierapolis, where the Roman theatre seats fifteen thousand, the necropolis extends two kilometres along the northern ridge, and the Antique Pool — fed by the same hot springs — scatters submerged column drums across its turquoise basin. The site opens daily at six-thirty, and early arrival secures the clearest water and the softest light for photography. Pamukkale day trips from Marmaris bundle the thirty-euro conservation fee, which grants access to both the travertines and the archaeological zone, alongside coach transport and a licensed guide. The springs emerge at thirty-six degrees Celsius, carrying dissolved calcium carbonate that precipitates on contact with air, building the rippled white formations at a rate of two millimetres per year. Visitors walk barefoot across the warm, textured stone, pausing in pools that range from ankle-deep to knee-high. The boardwalk route winds through sixteen active terraces, with roped sections protecting regeneration zones where flow has been redirected to repair overused areas. By early afternoon most tours allow time at the Hierapolis museum, housed in the restored Roman baths, before the return drive to the coast. The thermal pools remain open until eleven at night during summer months, but tour schedules prioritise morning visits to avoid midday heat and the arrival of larger groups.