Queen Camilla and first lady Melania Trump are teaming up for a rare joint outing on the final day of the U.S. state visit to the U.K.

On Sept. 18, the Queen, 77, and first lady of the U.S., 55, stepped out together to tour Queen Mary’s Dolls’ House and the Royal Library at Windsor Castle, two facets of the castle that might be of particular interest to Queen Camilla.

Last year, the Queen hosted a reception connected to the 100th anniversary of Queen Mary’s Dolls’ House, which the Royal Collection Trust touts as the world’s largest and most famous doll house.

Several objects with personal family ties stood out as Camilla guided the First Lady through the display. Among them were miniature books, each less than two inches tall, tucked inside the famous Doll’s House — a detail that quickly caught the attention of royal watchers. One was a contribution from Camilla’s son, food writer Tom Parker Bowles, whose aptly titled A Recipe Fit for a Queen was included in the set.

The late Queen Elizabeth‘s copy of the classic Alice in Wonderland was also on display, as was King Charles‘ set of Beatrix Potter.

A group of schoolchildren, who are writing and illustrating their own mini books for an art project, were also in the castle to meet the two women.

Literacy is also a key passion for Queen Camilla and a focus she’s made a priority of her royal work. The historic Royal Library at Windsor Castle features an extensive collection and the Queen and Melania viewed treasures from it together.

Those highlights included a poem and drawing from Queen Elizabeth I, and King Charles I’s annotated copy of Shakespeare’s Second Folio.

Melania, 55, and her husband, President Donald Trump, are in the U.K. from the U.S. on an official state visit at the invitation of King Charles.

The trip is historic as an unprecedented second state visit, as Trump becomes the first elected political leader in modern memory to be invited for two state visits by a British sovereign. He and Melania last visited in June 2019 during his first administration at the invitation of Queen Elizabeth.

The latest state visit officially kicked off on Wednesday, Sept. 17 and wraps on Thursday, Sept. 18, with the tours of Queen Mary’s Dolls’ House and the Royal Library providing an unusual opportunity for Queen Camilla and the American first lady to spend time together one-on-one.

The tours followed the Trumps’ formal farewell with the King and Queen earlier on Thursday.

On Thursday morning, local time, the royal couple bid farewell to the Trumps at Windsor Castle, where the American guests stayed and where the glam state banquet was held on Wednesday.

From there, Trump departed for engagements with British Prime Minister Keir Starmer at Chequers, the British premier’s country home in Buckinghamshire, while Melania stayed back at the castle for the tours with the Queen.

The first lady will then head to Frogmore Gardens for a Scouts-related outing with Kate Middleton, who is Joint President of the Scout Association, and then head to Chequers for the rest of the day’s schedule.