21 countries in 21 days?!

[midliferider]

If you're at the eastern end of Lake Constance, you can go Germany to Austria to Switzerland in about half an hour. Liechtenstein isn't far away either.

I did just that 2 weeks ago.

 

[andrew_s]

Certainly is a big ask... best route i can suggest would be
1. Holland
...
17. Greece
18. Bulgaria
...then maybe Romania, Moldova and Ukraine... better get peddling!

better to head back north - Serbia, Romania, Hungary.
at least you'll finish somewhere it doesn't take several more days to get home from.

 

[Jefferson Meriwether]

I've never done anything like that & have no idea if it's possible but it sounds like it would be an absolute blast giving it a try; I wish you all the best in your attempt.

Are you planning to do a progress report or anything like that on Facebook? If so I'll definitely follow it.

 

[machew]

Dliberately. I reckon if one is trying to cycle 21 countries in 21 days, then getting a ferry from one to another doesn't count

Cycle/walk though the tunnel. Other people have done it so it must be possible