@slowwalker,
I think you visited one of the great historical place of your country! Every country has such kind of place which had a great history against all invasions! My country has such kind of places as well! While the China made their great wall against Mongolian attacks the Korea used this place to fight against them! Amazing and I like the nature of this place that I see through your photography! Yeah it gives me Castle feeling when I see that first door to the temple!

Cheers~