@Daniele: The image at Turul Statue is more to the NW – as you can see it shows one more window and door of the parliament.
The picture that says 'Sándor Palace' is located at an incorrect location in Google maps. The named palace is located in the extension of the Széchenyi Chain Bridge, but you can see the bridge on the picture from the side, so the picture is taken more towards the south. ;-)
Hi Michael: almost convinced: your last link is from the "parapet below" of my comment. When I wrote 40 m, I considered the total 96 m for the Parliament; however it could have been 45, maximum 50. The link gives an almost perfect view, but if I look at the curved dome edge I conclude that the photo is taken higher than # 11330 (correct 60 m high).
At this point I would say more likely, a little lower:
or Sàndor Palace
@Daniele - Best thing is to look at the position of the building at the right, how exactly it is in front of the parliament, and how many windows you can see. This gives you an exact line on which the view point must be. That leaves only one option: this photo point.
The parliament is 96 m high (no other building is allowed to be higher).
The viewpoint is about 60 m above the river level.
@Michael I do not completely agree on your positioning especially for the elevation and I remain of the idea that the photo was taken lower, for example from a terrace of the Carlton Hotel. For me, the dome of the Parliament is higher than the photo's point, which does not seem more than 40 meters (35?) above the river level.
is taken a few meters south of your pin; it is easy to recognize the buildings on the right on the river: but here the perspective is different and it is not possible to see the National Assembly Office Building, the modern white building between the Parliament and the Margit bridge.
On the other hand this is taken from the Castle: perfect perspective, but too high, perhaps from the parapet below everything is Ok.
So I remain a little bit skeptical about the Buda Castle gardens and in any case I thank you for your work. PS: I've never been to Budapest.
@daniele Use my Google link and zoom in. You can see that it is the right angle, and not "north of Adam Clark Square."
Other evidence is that this image was taken from a higher altitude, so not "north of Adam Clark Square" as this is lower.
Sometimes I forget that someone uses the zoom :-(
True, Michael: I immediately gave up looking for the right building on the riverfront and put the pin in a panoramic outdoor spot. I see that in Michael's link the perspective is right; now I think of one of the buildings just north of Adam Clark Square.
I feel that when it is scenic vista then camera location should be marked and for buildings etc the actual location should be marked. At the most the coordinates of the camera location can be given.
I have added a marker there.
Evidence for this location: external link
Actually the location is off by about 700 m. The picture is taken almost straight from the south, over the bridge (Széchenyi Chain Bridge), from the Hungarian National Gallery, most likely the place just in front of it, whee the statue of Statue of Prince Eugene of Savoy is.
You can easily see this because of the building at the right, that is blocking part of the view.
@CuriousJM - Yes, I always look for the place where the photo was taken. In this case clearly from the hill on the other side of the Danube; in this sense the error should be less than 100 meters; I did not find the precise point. ;-)
@Daniele - your marker is about 900+ metres south-west of the actual location.
Your marked location is at 47.502080, 19.035822