Today, I went to Seoul Museum of History. 

So, I'll explain about 'Epic Poem' and 'Hopae'.

 Epic Poem was the first book written in Korean Alphabet.

This book tells us how the Joseon Dynasty was found.

I think it is important because it is written in korean Alphabet.

 Hopae was an ID card. On the front, there is the class, name and date of birth.

And back has the date of issue. People used it before entered the gate.

 I think Joseon Dynasty was important, and valuable.