Once a network of forts and garrisons designed to protect a king, “The Great Wall of Korea” is now a top tourist destination for people visiting Seoul.

The historic landmark sits about 20 miles outside of the city. Hwaseong Haenggung Palace was built in the 18th Century as a retreat center in times of war for King Jeongjo.

Legend has it that King Jeongjo would also stay at the palace to worship at the tomb of his father. For Koreans, the location highlights the importance of devotion to one’s parents.

While the palace is a sight to behold, the fortress around it is the true star.

The massive 3.5 mile wall encloses about half a square mile of land. The wall ranges in height between 13 and 20 feet. The majority of the wall is built of stone and brick. Over the years, the site has been well maintained and remains walkable today.

The location is visited by some 8 million people each year.

The openings throughout the wall would’ve been used to fire arrows and protect the king. They can now be used to spot some of Seoul’s most beautiful sights.