Tallinn TV Tower

This guide to the Tallinn TV Tower begins with an unlikely building material: concrete made not from ordinary aggregate but from ash left over from burning oil shale, the rock that once heated and lit this stretch of the Baltic. It follows the Tallinn Polytechnic scientists who spent years perfecting the mixture, the engineers racing to finish a broadcasting tower before the 1980 Olympic sailing events, and the slipform technique that let the trunk climb day and night. You'll hear how quickly the tower rose and how much of that ash concrete now sits above you. Look up at the tapering trunk and the needle antenna it carries before you step onto the ledge.