Manaca Iznaga tower in Valle de los Ingenios, also named...

TRINIDAD, SANCTI SPIRITUS, CUBA - 2014/07/23: Manaca Iznaga tower in Valle de los Ingenios, also named Valley de los Ingenios or Valley of the Sugar Mills, is a series of three interconnected valleys about 12 kilometres outside of Trinidad, Cuba which are a UNESCO world heritage site. The three valleys, San Luis, Santa Rosa and Meyer, were a centre for sugar production from the late 18th century until the late 19th century. At the peak of the industry in Cuba there were over fifty cane sugar mills in operation in the three valleys with over 30,000 slaves working in the mills and the sugar cane plantations that surrounded them. (Photo by Roberto Machado Noa/LightRocket via Getty Images)