Accra, Ghana (CNN)Melania Trump spent her second day in Ghana touring a former slave outpost and learning about some of the country’s tragic past, as part of her first solo trip abroad as first lady.

After receiving ceremonial permission to enter the area, Trump made the brief motorcade drive to Cape Coast Castle, a massive compound on the beach that was built in the mid-1600s. Originally a timber and gold trading outpost, the structure morphed into a “slave castle,” one of about 40 or so similar outposts used by foreigners to trade and purchase slaves, taking them from West Africa and into lives of unwilling servitude.

“This is a very special place,” said Trump, after spending almost an hour taking a tour with the museum’s director, Kwesi Essel-Blankson. “I will never forget the incredible experience and the stories that I heard.”

Trump, who had changed from her heels into flat-soled shoes in order to walk the vast Castle grounds, climbed the stairs of the various levels of the fort, and spent several minutes below ground to see the dungeon, where the slaves were held in tight, dark and dank cells before being traded.

On the wall near the dungeon entrance was a marble plaque that Trump stopped to read: “This plaque was unveiled by President Barack Obama and the First Lady Michelle Obama of the United States of America on the occasion of their visit to the Cape Coast Castle on the 11th day of July 2009.”

The first lady told the press her own visit to Cape Coast Castle was a memorable experience.

“The dungeons … what happened so many years ago. It’s really a tragedy,” she said.

Trump also walked through the fabled “Door of No Return,” an archway over a small tunnel that led from the main square of the interior castle down to the beach, where large waves crashed upon the shore. This was where the slaves would depart the castle and board slave ships. Trump laid a wreath of white flowers in memory.

Day two in #Ghana was so impactful. My visit to Cape Coast castle was a solemn reminder of a time in our history that should never be forgotten. Thank you to Chief Osabarima Kwesi Atta & the chieftains for the warm welcome & cultural ceremony. #FLOTUSinAfrica2018 pic.twitter.com/pdf9yrmQL8

— Melania Trump (@FLOTUS) October 3, 2018

At the end of her castle visit, Trump signed the guest book, telling the press she wrote, “thank you for your warm welcome. With love, Melania Trump.”