Yes, but we are talking about cities which are believe to be hundreds of miles down. We've only gone 8 miles down, who knows whats beyond that.

Some more interesting reads

Another piece of evidence pointing towards the theory that all heavenly bodies are hollow is that, as you would expect with a hollow sphere, both the Earth and our moon are known to "ring like a bell" when hit with a shock wave.

In "Moongate: Suppressed findings of The US Space Program" (1982), Nuclear Engineer and researcher/writer William L. Brian II presents evidence proving that the moon, as any hollow sphere would, "rings" when hit by asteroids or heavy space junk. And that's not all. According to Dr. Brian, "the evidence provided by Apollo seismic experiments also points to the conclusion that the moon is hollow and relatively rigid." (1)
He also reports:

According to the common concept that we have of our planet, the North Pole is a barren, frozen place where no self-respecting bacteria would live. And actually, that's basically what it is. But according to hollow Earth investigators, openings into the inner cavity are located in the polar regions, and warm air from the interior shapes an environment, in certain polar areas, amazingly different from anything which we probably imagine. There are no secrets in this regard, and all of the information was documented by the explorers at the time, but it is certainly not the kind of information to which we are exposed in our science classes at school.

For example, Dr. Fridtjof Nansen is considered one of the greatest Artic explorers of all time. His explorations and findings were taken so seriously that he was knighted by royalty upon returning to his native Norway. In the 1890s, Nansen organized a 15 month sleigh exploration, taking off from the ship Fram. He wrote in his book Farthest North about being at 77* North latitude: ' It was a strange feeling to be sailing away North ... over an open, rolling sea, ... we might have been hundreds of miles away in Southerly waters, the air was so mild for September at this latitude ... I have to ask myself if this is not a dream. '( P 120 ) Apparently, at that extremely Northern latitude, there should have been ice cover by September.

Originally posted by junglejake
How can the earth be hollow if it's flat

www.alaska.net...

Seriously, though, I did look into this several months back, there were a few threads addressing this then, too. Since then, I've looked into the theory even further, and I personally have become thoroughly convinced it is false. However, I have not read through the whole thread, just the first 2 posts. groingrinder must be a prophet

I'll look into this thread's arguements this weekend an state where the hollow earth arguements are weak or false based on current scientific theories and observations, and where the hollow earth theories are stronger then those currently accepted.

So in short, this was a chance to post an amuseing link, and a heads up infinite, keep up the search, never just accept something from someone who has an impressive title or appears to be inteligent!