Roger around the World

We are visiting one of the many caves in the bay.

Do you know what this is?

Before you start looking hard, trying to tell if it is built from the bottom or the top; stalagnite or stalagtite, I'll tell you what I think it is:

The true, raw manifestation of Time!

Time with a capital "T". If we were to commit the sin of cutting into this relic we would see the dinosaurs roam, the Mongolians attacking from millenia past.

The only constant for the past 4.000 years being the greenery on the hills, the water in the ocean and the never-bending Vietnamese. How deep into the calcified rock would that be?