Just north of the dusty border town of Chirundu, you will find a couple of hills covered in what at first glance look like large cylindrical columns of rock. Closer inspection reveals tree like rings on the cross section of each broken rock surface, and thus you have stumbled across 'petrified' trees 150 million years old! Now they did not get into a staring match with Medusa the Gorgon if she ever came to ancient Zambia... they were in fact over millions of years turned from cellulose to silica from the time they grew here during the formation of the Karoo system. Petrified trees are found all over the world and it can take a little as 100 years for trees to petrify. What makes these trees interesting is their size and age. They are easy to find, you just stop by the side of the road north of Chirundu, by a rusty National Monuments of Zambia sign post that marks the site and eventually a little woman called Esther who currently has two small twins on her back will give you a tour of the site with the hope that you will buy one of her many wonderful wood carvings. She is particularly keen for you to cross the road to see the 'really big trees on the other side'...so off you tramp, her twins staring at you from her shoulders, and at last you come across a series of mammoth, petrified trees lying on their sides broken in places but still in one long series that forms the whole tree ...its worth the stop, even if you just want to wander up the hill for a great view of Chirundu and the great Zambezi river glimmering away in the distance.