I'm sure I answered this but the post has disappeared. Maybe someone didn't trust my link?
They only occur in eastern Germany and the Black Forest – they've been gone for 65 years from where I live (the low west of the country).
I think Igonz1088 means:
The biggest number of national rarities seen in one day / present in one place in the ABA area / UK / WP?
But I don't think Peregrine Falcon is a national rarity!
The largest number for a national rare in a day in the Netherlands is probably a flock of 61 Griffon...
There is a guy round my parts who will enter observations of locally rare birds with photo or even video. One time, he entered an observation for a Spotted Redshank at a local marsh, which is rather unsuitable for waders but hey: you never know. His video showed a Spotted Redshank parading past...
I had a Camberwell Beauty flying over my head on the 12th at my German local patch. I had been looking for them as there was a small invasion in the Netherlands... just a shame I did not get a picture!
I was too lazy to cycle to a Purple Heron that was 1.5 h away... It was also much easier to photograph from the car (I'll stick to that excuse).
(Middle Spotted Woodpecker is not too hard to find for me, but I still enjoyed adding it to my "house list" this week!)
You can also fly from Salalah to Muscat to avoid the drive.
I'd assume quite a few Caribbean islands are easy enough on your own (I've only been to Aruba which does not have much to go for, although finding a new bird for the island is quite easy).
Driving around in SE Brazil is easy enough...
Patterned camouflage wear is famously forbidden in Trinidad and Tobago.
Wearing army-like camouflage is also a bad idea if you are in a country where guerilla-or poacher-like types are likely to meet a "shoot first, ask questions later" policy.
These chances are minimal (I hope!) at your local...