Photo source unknown. Location unknown.*
*Update: Bruno Castello recognized the location as Tianmen Cave ("Tianmen Dong") in China. The title of my post was somewhat tongue-in-cheek, but now I discover that "tianmen" translates to "gate to heaven."
Although described as a "cave," it is clearly a natural bridge*, which surprisingly formed within recorded historic time (known history for China stretches back an amazing distance - in this case to the "sixth year of the Wuyong Period of the Three Kingdoms" - the year 263) when the wall underneath the arch collapsed.
More history and some additional pix:
The Climbing Heaven Stairs has a total of 999 steps, the number 9 is again referring to the number of palaces in heaven.For comparison, the Washington Monument in Washington, D.C. has 897 steps. The Gateway Arch in St. Louis has 1076.
From the way the stairs look, it would seem that there would be rest stops with the stairs flattening to let climbers rest, but this is actually an illusion. To my horror, there is no flat surface... little space for resting in the relentless climb up towards the hole. With the amount of people climbing up, you do not want to be in the way either. I would just try to catch my breath ever few minutes and continue in my march to the top...
Hat tip to Bruno for making this post more interesting!
Correction: The USGS standards would call this a natural arch, not a natural bridge - the latter term used only when water carves the passageway.
Addendum: Video of planes flying through the arch to celebrate the new millenium (thanks chorn74).