First lady Melania Trump had an “emotional” second day in Africa visiting a former slave holding facility in Ghana.

Trump toured Cape Coast Castle on Wednesday, first seeking permission from local tribe leader Osabarimba Kwesi Atta II, as is customary.

The two met in the Obama Hall of Emintsimadze Palace, named after former President Barack Obama who visited the castle with his family in 2009. Obama compared his visit to Cape Coast Castle, a major outpost for transatlantic slave trade, to his experience visiting a Holocaust concentration camp.

An estimated 20 million slaves passed through the dozens of trading forts in Ghana. Cape Coast Castle shipped a majority of slaves held there to America.

Trump spent several minutes in one of the castle’s dungeons, where slaves were held in terrible conditions until they were sent abroad. She walked through the “door of no return,” where slaves were brought inside the fort, and laid a wreath near a dungeon door.

“It’s very emotional,” Trump said. “I will never forget the incredible experience and the stories that I heard. … The dungeons that I saw ... what happened so many years ago, it’s really a tragedy.”

It’s Trump’s second day in Ghana. On Tuesday, she passed out teddy bears and blankets to mothers and their children at a Ghanaian hospital and had tea with first lady Rebecca Akufo-Addo.

Trump’s five-day tour of Africa is part of her “Be Best” initiative, which focuses on the well-being of children, promoting positive practices on social media, and fighting opioid abuse.

She will visit Malawi, Kenya, and Egypt later in the week.