That's the 700-year-old tomb of Suleyman Shah.
He was grandfather of the founder of the Ottoman Empire, or modern-day Turkey.
It sits in a Turkish enclave of northern Syria, about an hour and a half south of the Turkish border by car.
The tomb is suddenly front and center in Turkey's role against against Islamic State fighters in Syria.
The militants are said to be advancing on the stone mausoleum, which is guarded by several dozen Turkish soldiers.
The Sunni militants consider tombs a form of idolatry and have been destroying similar sites during their advance.
A decades-old treaty makes the tomb sovereign Turkish territory, and Ankara vowed back in March to defend the mausoleum if it's attacked.
That scenario is suddenly looking a little more likely.
On Tuesday, Turkey sent a proposal to parliament to beef up its powers to order cross-border operations in Syria and Iraq.
