The Giro d'Italia has been to Israel and was supposed to go to Hungary last year. The Vuelta a Espana has been to Belgium and the Netherlands. It is not just countries next to the host country that can have these races.
Also, I hope you can get enough nominations to get this quiz featured. I see we both have made 100+ quizzes with 12,000+ takes but with no feature yet. I think this might be the one for you!
I think San Marino may get a pass-through in 2024 when the Tour starts in Emilia-Romagna. The 2025 Grand Depart is in the Netherlands, so it will pass through some combo of Belgium, Luxembourg, and Germany (if not all). I could see Portugal, Slovenia, Norway, and Sweden being on the list as well. Slovenia is a cycling-mad country, with some of the biggest stars in the peloton being from Slovenia, and the atmosphere would be like it was when it started in Denmark.
San Marino did get a pass through in Stage 1 of the 2024 Tour de France. There was a Category 3 mountain, the Cote de San Marino, about 30km from the finish of the stage.
I think they would need a couple rest days to get back to France. It would also be cool to start in French Polynesia. I'm sure a lot of people would like to visit Tahiti. Logistics might be a bit challenging, though.
I was wrong, sorry.
Tour de France started in Dublin in 1998 and a ferry service began in 1969.