炼丹炉一直很神秘，现在我们就要近距离接触它了。

炼丹炉位于一座荆棘丛生的山峦上，距山下约2.5千米，与说经台所在山峰遥相呼应。炼丹炉是一座青砖砌成的方形石室，长3.6米，宽2.7米，高约2米。室顶呈八棱形，象征八卦。室内有残损青石雕像一尊。从炼丹炉沿东南扶栏盘旋而上，可领略“仰天池”风光。相传“仰天池”是老子当年冶炼长生不老丹蘸火的池子。

The Liandan Furnace is always so myste－rious and now we will have a close contact with it.

The Liandan Furnace stands on a lofty hill overgrown with brambles and far from the Shuojing Platform.The furnace is two kilometers and half downhill.It is a blue－bricked structure in the shape of an octagon.It's 3.6 meters long，2.7 meters wide and 2 meters high.The octagonal shape repre sents the Eight Diagrams or rather the eight combina tions of three whole or broken lines previously used in divination.There is also a spoilt marble statue within.The twisting and twining path southeast of the Liandan Furnace leads to the Yangtian Pool.Leg end says that it is the very pool where Laozi gave cold treatment to his elixir.