Borough Market has opened a new educational centre.
The Market Hall will be used as a classroom and kitchen to help visitors learn more about the Market and the food it sells.
Prince Charles looked right at home, inspecting a haunch of wild boar and sampling luxury olive oils.
A farmer himself, and an advocate of organic food, he took special interest in the produce being sold at many of the stalls.
But, it looked rather more incongruous when Charles started sipping on a cup of "builder's tea".
The Prince normally has his tea without milk and with a spoonful of honey, but he ordered one with two sugars and as strong as you can make it from cafe-owner Maria Moruzzi.
Prince Charles and the Duchess of Cornwall paid a visit to one of London's oldest, most famous food markets today.
The royal couple were in Borough Market to meet traders at the Old Hall.
It was forced to close two years ago, because of rail construction work, but the stalls are now back in business, as Liz Wickham reports.
The Duchess of Cornwall was presented with armfuls of gifts from traders, as she toured Borough Market.
Florist Sharon Crane, 45, whose business opened today, gave her first bunch of flowers to the Duchess for free.
Afterwards she said: "I told her 'I'm giving you a bouquet of flowers in case your husband forgets' and she said she was hoping to get some."
She was also presented with a massive chocolate heart, decorated with the words "with love from Borough Market".
But it seems Charles is having a rather less romantic Valentine's day. When asked by David Ruane, a worker from a nearby pub, if he'd received a card, he rolled his eyes and said: "No, I don't think so."
The Prince of Wales waved away the offer of a free chocolate brownie, as he re-opened Borough Market today, saying that he'd given them up for Lent.
But the Duchess of Cornwall happily accepted a Valentine's gift of a large chocolate heart decorated with the words "love from Borough Market".
She told chocolatier Hayleigh Bazelya: "I will have no problem munching my way through that."
The Prince of Wales and The Duchess of Cornwall have officially re-opened Borough Market.
Most of the stalls had to move out two years ago, because of rail construction work, but they're now back in business.
There is flash photography throughout Sharon Thomas' report.
Borough Market's largest trading area, Three Crown Square, reopens today after being closed for over three years. The section of the market was closed In 2009, due to works being carried out by Network Rail.
School children have had a chance to hit Borough Market and sell fruit and veg they've grown themselves today.
Emma Walden went to see how they were getting on.
Children from St Mary Magdalene Church of England Primary School are among those selling the fruits - and veg - of their labours at Borough Market today.
Here are some pictures of them planting their seeds earlier in the year.