Hello, I'm Steve Jones and I'm going to tell you a little about water springs. Now, in the past, of course, water springs were very important, because people needed fresh water. And fresh water, usually, did not come out of the sea. And very often, not even in rivers. Although rivers were generally alright, because they were not salt water. But, it was very important that somehow the water which came from rain, and what we call the water cycle, was collected somehow and was usable for say, a village. Now, the surface of the land is covered by, what is usually a fairly thin layer of soil. Underneath that, you can find the various different layers of rock. And these rocks are sometimes, impervious, that is, water can not go through them. So, what happens is, in these layers of rock, which are permeable. So, these are permeable, that is, water can go through them. Rocks like limestone, and sandstone are permeable rocks. So, with these rocks, the water soaks through the rocks, until it reaches a layer, of say, clay. This could be clay, and once it's reached that clay, it can go no further. So, what it then does, is follow the contour, remembering it has to obey the laws of gravity, and therefore it's going to go downhill and not up hill. It will flow along that surface, until it comes to the land surface. And at that point, you will see a spring. That is, the water that is collected over this large area comes out through, usually a line of small springs, and then flows down, and into a stream. It produces a stream that flows into a river. So, this is the purvey, this is the way that the spring actually is created. This is very important, this spring. Because the water from a spring is quite pure. First of all, as rain, it is full of various impurities. It hits the soil surface and the soil begins a filtering process. And as it passes through different layers of rock, the filtering continues. So, by the "sime", time the water reaches the spring, it is actually quite pure and very drinkable. So, when we consider water springs, and if you look at old maps, you'll always find that next to a water spring, very often is a temple, if it's in Roman times or Greek times. You'll find a temple there, because this was a very important thing. Pure, drinkable water. So, here we have water springs, the source of pure, drinkable, clean water.