Although the Kazenyi Torets river runs through four major towns and is flanked by a railway and a road, you could drive the length of its valley without setting eyes on it. Hidden for most of its length by a thick band of marshy woodland on either bank, its waters are mostly left to kingfishers and frogs.

Crucially, though, this placid river runs through the centre of the last quarter of Donetsk region held by Ukraine, and the string of towns on its banks have been forged into a fortress – a near-impregnable stronghold that has resisted Russian attacks for more than a decade.

Eleven years ago, I watched the war in Ukraine begin on its banks. Three years ago, I sat again by the river and wondered as Russian shelling grew closer if it was the last time I would see it. Now, it is at the very heart of contentious negotiations to end the war.