Hotel Royal on Unter den Linden.

Unter den Linden (German: "under the linden trees") is a boulevard in the central Mitte district of Berlin, the capital of Germany. Running from the City Palace to Brandenburg Gate, it is named after the linden (lime) trees that line the grassed pedestrian mall on the median and the two broad carriageways. The avenue links numerous Berlin sights, landmarks and rivers for sightseeing.

Wikipedia