https://themodernhouse.com/sales-list/thomas-more-house-ii
https://themodernhouse.com/sales-list/Lauderdale-Tower-II
https://themodernhouse.com/sales-list/willoughby-house
https://themodernhouse.com/sales-list/ben-jonson-house-iii
And all are sold on that weird UK feudal relic, leaseholds, so you're just buying for a certain number of years - a couple of the ones above only have ~80 years remaining.