Nice article, Tim. Great to see a piece on Porto that lifts the focus from the magnificent harbour to the old town, and with such passion. (And I love the orange raincoat in your art nouveau street corner photo.) The cost of maintaining old European cities is astronomical: in France the "heritage" budget crept over € 1 billion for 2021, and despite this, so many historical buildings up and down the country are in a state of, well, decrepitude. Yet renovating them is probably a lot better environmentally, not least for the climate, than demolishing and building (often not very sustainable) new ones in their place. Even real estate agents are waking up to this, with one blog on Savills website going as far as to say that "historic buildings represent a significant opportunity in the drive to reduce carbon consumption". This argument should give Porto and UNESCO a boost.