One of the most thrilling things for me, aside from simply being back in a land that I love, was finding missing pieces in my research--like realizing the current Buda castle is three times the size of the castle that would have stood there in 1848. (This block, below, is essentially the only part of the castle that existed then--not the gaudy dome that everyone knows from pictures of the city).
But there were other discoveries that thrilled me because most tourists had no idea of their significance.
Like finding the Karolyi palace, where Karolina Karolyi (an ardent patriot who makes a cameo appearance in my book) lives.
Or Cafe Pilvax, where the young men of March planned their revolution (though the current incarnation looks nothing like the pictures I've seen). It was just around the corner from our apartment.
Or this: this lovely building is the Vigado, some kind of music hall. But it was significant to me because it was one of those aha! research moments. I'd been trying to find out where the Redoute was, a public ballroom used frequently in 19th century Budapest. In a local guidebook our host left in the apartment, I discovered why I couldn't find the ballroom. The original building had been destroyed by canon fire during the 1849 siege of Budapest: this was built on the site.
Probably my favorite discovery, though, was this little street not far from Buda castle. There are some lovely baroque palaces there: this is one of them, though in the 19th century it was used as a prison to house political prisoners, and I use it in my story as the prison that my heroine has to fight her way to get to. So imagine, if you will, this seemingly pedestrian street filled with soldiers (and maybe a dragon or griffin or two).