The 400-foot-long, John Brown-designed "former floating palace" of the late Queen Elizabeth II was commissioned by King George VI in 1952. Following her father's death and her coronation, Elizabeth set sail on Her Majesty's Yacht Britannia in 1954. The queen was fond of the ship, which she once described as "the one place where I can truly relax." During Britannia's 40-plus year operation, it hosted several royal honeymoons, including that of King Charles III (then Prince Charles) and Princess Diana, and provided transportation for official royal visits. 

The luxurious yacht featured a drawing room, dining room, two sitting rooms, spacious crew accommodations, elevator, wine cellar, official reception room with fireplace and baby grand piano, and ornate staterooms with private bathrooms and dressing rooms. The New York Times described the royal apartments as "[giving] way to the homey, patched elbow chic of an English country house, with flowered chintz slipcovers, family photographs, and rattan settees, interspersed with the occasional relic of Empire." And then there was the sun lounge, which was the queen's favorite space.

The Britannia's operating and maintenance costs eventually led to its decommissioning in 1997. These days, the yacht is stationed in Edinburgh for all to see — TripAdvisor gave the excursion the Travelers' Choice Best of the Best award in 2023. Tickets include a self-guided audio tour and access to all five decks, which include the state apartments and sun lounge, while the Royal Deck Tearoom offers the opportunity to enjoy food and beverages aboard.