Britain’s Queen Elizabeth II made a surprise appearance at the opening of a new cross-London rail line named in her honor today, demonstrating that despite reported mobility issues she’s still able to get out and about when she wants to. The 96-year-old monarch has been largely confined to Windsor Castle in recent months, except for an appearance at a memorial service to her late husband, Prince Philip, in March. This past week, however, there’s been no stopping her, with two visits to a Windsor horse show and, on Tuesday, the launch of the new Elizabeth Line at Paddington station. It wasn’t exactly the opening of an envelope, though—the new line, linking 41 stations to the west, east, and southeast of London, has been under construction since 2009 and has cost almost $24 billion.