https://ifers.123.st/ is a great resource, one that is full of information that has been vetted by those that care.

my days of trying to convince anyone are over.

If you care enough to find out, it is obvious.

if you choose not to look, that so be it.

if the earth might be a little hollow or maybe very hollow.

seems very probable that there are cities below us.

given the information we have about the size of the caverns we have found.