This puzzle is part 24 of Gladys' journey across the globe. Each part can be solved independently. Nevertheless, if you are new to the series, feel free to start at the beginning: Introducing Gladys.
Dear Puzzling,
By the time you receive this message, I may have already returned from my trip. Today I visited a luxurious mansion built by an important person. I hope your board game skills are not rusty, because you'll need them for today's puzzle!
Wish you were here!
Love, Gladys.
Across
1. Large inlet
5. Local name for Scotland
9. More delicate
10. A place where a fly is a nuisance
11. An African country or its capital city
15. Less feral
16. A Uruk-hai, for example
18. Native of an Arab state
19. Zilch
20. Precious stone
21. Card below trey
22. EvaluatedDown
1. Perfect is the enemy of —
2. Prefix for -cycle or -brow
3. Short-range network
4. — as a fiddle
5. Arsenals
6. Instead of = in — of
7. Grandmaster Larsen
8. Newspaper piece
12. Outlaw assassinated by coward
13. Members of the clergy
14. Arizona landmark: Horseshoe —
15. Ancient Roman attire
16. Legal obligation
17. Sushi ingredient
Gladys will return in "Thousands and thousands of words".