Explanation: It may be too extreme - too positive, so I will leave that up to you. It all depends on how far you want to go
What about something along the lines of
3000 years of cacao history up close and hands-on in an "architectural masterpiece" on the Rhine.
Or "architectural tour de force", "architectural showpiece"
or "work of architectural ingenuity"
msherms Germany Native speaker of: English PRO pts in category: 4
The translation workplace 
