The article below copy from www.mymountaingoal.com/waterfall_rainbow.htm
Rainbow waterfall is accessible from Sungai Lembing town which is located 45 kilometres from Kuantan.
Sungai Lembing used to be a busy mining town and housed the largest underground tine mine in the world – today it is almost deserted since it is simply no longer economic to continue mining in the area.
From Sungai Lembing to the starting point of the waterfall take about 45 minit driving time. In early day we need to take 4WD to go into the starting point of this waterfall but now can just go in by car. After parking the car (is one of our camp site too) we need to cross the river and take one and half hour to trek into the waterfall.
This water is a bit difference with other waterfall, it is like a small mountain that has been sliced out a small piece in the middle and we just follow the sliced out part trek into there. At the end of the trek, a big natural vertical wall appear in front of us and 75 degree slope on both side grow with small plants.The water is broken up and reaches the bottom as mist and in the process forms a rainbow usually between sunrise and 11am when the sun is at a certain angle. Is this place is a garden it must be the most beautiful waterfall garden in Malaysia.
林明(Sungai Lembing)位于彭亨州境内,，从吉隆坡驱车5小时车程。它曾经是马来西亚最大的锡矿场之一。
林明山是许多人喜爱看日出及云海的地方，但对经常翻山越岭、游河赏瀑的人来说不过尔尔。反之离林明约1小时车程的彩虹瀑布却让人有一种与世隔绝的感觉。
彩虹瀑布，只是一个普通彩虹在瀑布下的景色，但若此彩虹及瀑布出现在一个世外桃原般的环境之下，它确实值得我们去欣赏。小溪水从一百米以上的高度沿着垂直的自然高墙流下，沿途打在凹凸不平的岩石上形成细小水花散落在布满岩石的小潭上，使周围环境的空气显得潮湿，羊齿植物因此寄生在自然高墙上，而从高度散落下来的水花在清晨阳光照射下形成了一个半圆七色彩虹，使高墙两旁75度斜坡上绿油油的植物也显得有生气。从其地形推测相信它是一座由土崩而形成的瀑布。它的形状有如一座山被切了一块般，剩下一片3面环山的花园。它唯一的进口也是唯一的出口，是由一堆大小不同的杂乱无章的岩石顺着地势的高低堆积而成的。
岩与岩之间隙缝使小植物(杂草等)找到生存的小空间，如此一来岩石与小植物使入口处显得有一点有一点狭窄，并且将花园内一半以上的景色遮盖者，使这自然花园充满了一种神秘感。
小潭内的水随着地势的高低在岩石间的隙缝分散川流而出再汇聚成小溪，沿着小溪顺流而下，一路上呈现在眼前的都是一些大石、水潭及小瀑布，小岩和小溪两旁就是我们常见的热带雨林及土崩痕迹。从瀑布沿着小溪步行大约1小时就会看到小溪与河流(Sg Lembing)的接口，河流对岸确是一片被开发后留下的荒沙平地。
想象你坐在冰冷的岩石上，微风轻拂在您身上，面对着百米高的自然高墙，望着水花散落在水潭上，赏着七色彩虹有如一座桥梁横渡高墙两旁斜坡上绿油油的植物，如此景色是多么地令人难以忘怀。希望森林在高度开发之后还保留着这么一个充满神秘及幽静的自然花园。
More photos 更多照片:- http://www.sunbrightnu.net/?page_id=21&album=60&gallery=71
