https://www.howandwhys.com/two-mountains-100-times-higher-than-mt-everest-found-inside-earth/
In any case, many people say that the entrance to the hollow Earth exists. This is confirmed by satellite images of the North Pole taken in 1968. A hole is visible on them, which may indicate that this is the end of one of the empty structures. However, this conclusion has not been formally confirmed yet.
Only in 2014, an expedition was planned in search of penetration into this underworld, but its organizers began to disappear under mysterious circumstances. For this reason, the company ended in failure.