What do you believe is at the center of our Earth? Oh come on now, think of something and then put it in the comments at the bottom of this post. First, tell us if you think it is solid or liquid.
After you get just a few feet under the surface away from the heating effect of the sun, you will find the coolest area under the earths surface. That is why before refrigeration was widely available, fruit cellars where common in most homes. The home I grew up in had a fruit cellar, a separate small room off the main cellar that had no windows and no access to the outside. It was always nice and cool in there, even in the middle of the summer.
OK, lets start down from the Earth's surface. For every 70 feet that you descend in a mine, the temperature goes up one degree Fahrenheit, or for you who prefer metric, it increases one degree Celsius for every forty meters of depth. So why does it get warmer the deeper you go and the further away you get from the effects of the sun? Most geologists believe that radioactive decay of deep interior stuff may be the cause of all that heat. Heck, they can't fool me, that is where the Devil lives, right?
Now, we have gotten close to what is in the center, but we are not quite there yet. So, what is in the center? First of all, it is a place of zero gravity. It also is a very wealthy place. Most people think that the center of the Earth is liquid. Heck, that is what I have always been taught, but now they are saying that it is solid. It is made up of sturdy nickel-iron and is sprinkled with enough gold and platinum to pave the entire earth's surface one and half feet thick. Now, I wouldn't recommend trying to put a mine down that deep, it would be impossible with any foreseeable technology.
So, a journey to the center of the Earth would not be a very pleasant thing. It sure wouldn't be like the old movie that showed a beautiful prehistoric place with dinosaurs, etc. I prefer living on the surface of this earth where I can see the floral and fauna, don't you? Now enjoy this beautiful Earth and have a great day, you hear?