As Tom says No 3 is Humewood in South Africa and No 18 is Gavea in Brazil.
A few more hints:
1. Last letter of the alphabet - look up the last courses in a few handbooks/directories - Alpine Europe.
2. Decadence in a utilitarian society - Trent Jones family doing their bit for East-West relations.
3. Humewood (South Africa)
4. Same continent - get 3 and work north - rather a long way - and a famous period piece colonial novel/expose.
5. Tucker's Point (formerly Castle Harbour) (Bermuda).
6. Carries the name of a major North American city, a long way west in an often neglected country of North America.
7. Barwon Heads (Australia).
8. Domurgsche (Netherlands).
9. Real Pedrena (Spain)
10. Formosa (New Zealand)
11. La Dehesa (Chile)
12. Should have been Ullna (Sweden)
13. Two courses - one apparently in the British links style, the other apparently in an American style. Has a greenkeeping deal with ANGC - apparently. Not easy to give a clue. Have a look at the Low Countries.
14. When I say best paid, I include (particularly) Tiger- who has been one of his biggest paymasters and who has paid him to appear at some less than classic venues?
15. Right next door to a world-famous links with the same surname, as it were. 'Sure it is'.
16. Queenwood (England).
17. The initial we need for the 'alphabet' is of no use. Try to identify the type of countryside - it is (from the air) remarkably similar to a number of other courses in and around a major city- in France
18. Gavea (Brazil)
19. European heathland close to the shore. Scandinavia awaits your discovery of it.
20. West Monmouthshire (Wales) - highest golf course in UK - mountain golf, but doesn't it look like links!
21. A hard one - there are more golf courses to choose from in this coun try than any other - and you have to know what letter you are looking for. I only chose it because it has an unpronounceable name in a land of unpronounceable golf courses. It's not far from Pittsburgh, although that doesn't help with its initial letter.
22. Oporto (Portugal)
23. Askernish (Scotland)
24. There won't be any litter in this country - a useful journey break twixt Australia and the UK.
25. A nightmare for early editions of World Atlas of Golf - they changed the nines for club play and competition play, rather like K-Club. Unfortunately there has just been a horrible night-club fire in this country.
26. The airport in the top of the picture is no longer the city's main airport. When I was there they were using this particular airport for police and military training for a forthcoming Olympic Games. There was a rather sad looking 747 being blown to pieces with explosives and troops running into it while i tried to concentrate on 5-irons and putts. Pericles is probably turning in his grave.