A construction boom in Myanmar is fueling a demand for raw materials like limestone and sand. Extracting these resources threatens ecosystems and communities along the Salween River.This push for economic and industrial development is also driving plans to build megadams on the Salween River.Activists call for an alternative vision for development, based on sustainable technologies and small-scale, decentralized projects. Tun Lin, the 36-year-old security guard who mans the door to the Linno cave – home to four species of bat. Photo by Demelza Stokes. Tun Lin has a unique occupation: he is the security guard at Linno limestone karst cave on the bank of the Salween River in Myanmar’s southeast Karen (Kayin) State. He earns 80,000 Myanmar kyat (around $60) per month to guard the entrance to the cave, the contents of which — common nectar bats (Eonycteris spelaea), wrinkle-lipped bats (Chaerephon plicatus), Theobold’s tomb bats (Taphozous theobaldi), black-bearded tomb bats (Taphozous melanopogon) and a lot of guano — are targeted by robbers who either poach the bats or steal the guano that is sold in the local area for use as fertilizer. Only five months on the job, the 36-year-old has not yet encountered any thieves, but the last time hunters came, they used nets to scoop up over a thousand of the cave-dwelling bats. Captured live and kept in bags, the bats were sold on as food or as traditional medicine, explained Myint Myint Nwe, the cave’s license holder and customary “owner.” But it’s not just the cave bat colonies that are at risk here in Karen State. In fact, the entire limestone karst landscape, and its natural formations and caves are increasingly at risk from Myanmar’s (and Southeast Asia’s) booming construction industry, the bedrock of surging industrial development. This is the final article in a five-part series exploring Myanmar’s Salween landscape amid galvanizing plans to develop hydropower projects along its course. Part I outlines plans being made by businesses and governments in China, Thailand and Myanmar to harness the Salween’s vast hydroelectric potential. Part II looks at the Salween dams’ already bloody legacy and the projects’ direct or indirect relationship with perpetuating instability and conflict in Myanmar’s Shan and Karen states. Part III uncovers some of the ethnic and ecological biodiversity at stake, focusing on the Kun Heng “thousand islands,” a unique riverine ecology facing submersion under the Mong Ton dam reservoir in Shan State. Part IV introduces the “Salween Peace Park,” combining wildlife conservation and peace-building in Karen State, where the world’s longest running civil war has raged since 1949.