Why are you so sceptic that this is not a realistic request?
In my early private flying days I had a lot of those offers to my close friends, something like "Hey I got to nail down some flying hours. Just choose a destination and we go there!"
Presumably it is a similar setup here. Okay, way more decadent but also on this level there are some flying owners who can afford this.
Now back to the topic:
How about St. Petersburg in Russia?
Haven't been there but heard that it's a magnificient city at the sea, especially in the summertime when it is relatively mild (around 20°) and the days almost never end in the so called "white nights". It is a city with an impressive history and a lot of cultural attractions.
Also I assume that there are a lot other biz jets stationed there, so your Hawker will have adequate company
