“Excuse me, what is a lighthouse?” I overheard a foreign visitor enquire.

A fanfare welcome to Trinity House.

It was easy to point to an answer since there were two right there: either side of the door. While some of London’s grand old buildings illuminate their entrances with coach lamps, and others blazing torchères, Trinity House offers the beams of twin model lighthouses. You’d expect no less of the flagship headquarters of an organisation in charge of the safety of shipping since it was granted a charter by King Henry VIII.

One of the twin lighthouses that illuminate the entrance at Trinity House

Yesterday was a quite an occasion: a rare Open Day to celebrate 500 years since Trinity House’s foundation in 1514. Since then the corporation has set up beacons all around Britain. It now operates some 600 lighthouses and lightships—the former mainly on the rocky west coast and the latter largely off the lower-lying and sandy eastern shores—as well as supporting seafarers and their families. It also has a strong engineering and technology remit, and spearheads development in satellite navigation and piloting of ships.

Trinity House, celebrating 500 years. The building, by Samuel Wyatt, dates from 1796.

A grand, double staircase curves up to the first floor past globes and coats of arms, to reach a row of high-ceilinged rooms that look out towards the Tower of London and Tower Bridge. Walls are decorated with portraits of royals associated with Trinity House, from the Tudor monarchs right up to the current Master, Princess Anne. Other notables depicted include past Master Winston Churchill, shown signing the Atlantic agreement with Franklin D. Roosevelt. Oil paintings of storm-lashed vessels at sea and model ships including Nelson’s Victory and Cutty Sark, plus the Court Room’s lavish ceiling, add a touch of drama.

King Henry VIII, who gave Trinity House its charter, presides over the Court Room.

In the library there’s a display of silverware, including grand table ornaments shaped like lighthouses and a magnificent wine cooler that’s a riot of sculpted corals and shells. I imagined an admiral hosting dinner here, musicians playing in the minstrels’ gallery above, as these objets d’art glinted beneath the chandeliers. In the adjacent Pepys Room there’s a portrait of the diarist; Samuel Pepys was Master of Trinity House shortly after the Civil War.

Portrait of Queen Elizabeth I by George Gower.

As I continued to nose around the cannon balls, the bell from Her Majesty’s Royal Yacht Britannia, globes and coats of arms, hordes of visitors came flowing in. Many were from overseas, had just arrived by chance and were really excited to find themselves inside such a venerable place. We may not have been private guests invited to the captain’s table, but it was a real party atmosphere. Here’s to the next 500 years, Trinity House. Carry on lighting the way.

Trinity House will be free to explore once again as part of Open House weekend (20 September) or you can visit their website to book guided tours. Find out more in their appropriately named magazine, Flash.