MBC
I would say that one of the easiest is Ireland/UK as their citizens can move freely between both borders
Take it with humor:
What nonsense are you giving here man? You speak the same language, you have the same everything. Unfortunately, you live on an island like Robinson Crusoe and Friday.
You can drive from one side of the island to the other side of the island in no time and that's all -no cultural upheaval - no change.
We who live in a community of states and nations together without borders in a beautiful world called the EU -we are in a community that gives us joy - the security of handshakes, traveling to different cuisines, and it's just different from an island prison.
Example:
I live in the Moravian part of the Czech Republic https://cs.wikipedia.org/wiki/Slov%C3%A1cko
-In half an hour by car I am at the border with Slovakia and in 1.5 hours by highway I am with my sister in the central part of the Slovak Republic - even though she lives in the city center in an apartment, she owns a mountain hut in the Malá Fatra mountains and in half an hour I am in the at a height of 1,400 m on mountains full of pistes for sledders and tracks for cross ( slopes for skiers)-country skiers. https://cs.wikipedia.org/wiki/Martinsk%C3%A9_hole
And this is a different nation - a different language, sharper cuisine and also sharper people, but our brothers and sisters and mountains and sports fields are a joy to look at.
https://www.google.com/search?sca_esv=596408074&rlz=1C1NHXL_csCZ927CZ927&sxsrf=AM9HkKkS7CyzZv6hfDCTfqg4-nLInYkFrA:1704660505937&q=slovensk%C3%A1+kuchyn%C4%9B&tbm=isch&source=lnms&sa=X&sqi=2&ved=2ahUKEwiS06yfk8yDAxXBh_0HHQwpD_QQ0pQJegQIDRAB&biw=1242&bih=552&dpr=1
In an hour's drive I'm at the border with Austria - different language, different cuisine, and it's 2 hours to
https://www.wien.info/cs/aktualne-z-vidne/zima-ve-vidni/v%C3%A1no%C4%8Dn%C3%AD-trhy-v%C3%ADde%C5%88-je-v-dob%C4%9B-v%C3%A1noc-kr%C3%A1sn%C3%A1-342688
https://cs.wikipedia.org/wiki/V%C3%ADde%C5%88
https://www.booking.com/city/at/solden.de.html?gclid=Cj0KCQiAtOmsBhCnARIsAGPa5yaUeR86L-Nqn0YsTf2ZuHQozy_AGYQfu9c6sxVpeVzLk0gqMcJjMTEaAgGFEALw_wcB;aid=339272;ws=;label=city-solden-t9VlwlOuL13Cpnr4tAHbggS387630669089%3Apl%3Ata%3Ap1340%3Ap2%3Aac%3Aap%3Aneg%3Afi%3Atikwd-273221798%3Alp1003739%3Ali%3Adec%3Adm%3Appccp%3DUmFuZG9tSVYkc2RlIyh9YcUc3ZfdbbfEWXOoFXTjaLE;gad_source=1
Due to the low prices and zero tax on groceries, my son drives to POLAND to make large purchases -he takes two friends in the car (so that they share the cost of transport and it is advantageous) -Also Poland two hours by car
https://search.seznam.cz/obrazky/?q=v%C5%A1echny%20tr%C5%BEnice%20v%20polsku
https://www.polsko.travel/cz/za-nakupy-2
Those who are closer to Germany go to Germany - on buying cheaper food and in general also for culture.
For three hours by car, maybe less, I am in Hungary - different culture, different cuisine, different customs
https://www.google.com/search?sca_esv=596408074&rlz=1C1NHXL_csCZ927CZ927&sxsrf=AM9HkKlDV_Awt2uhdQK4MncdkWaeY-FK_Q:1704660563974&q=Madarsk%C3%A1+kuchyn%C4%9B&tbm=isch&source=lnms&sa=X&ved=2ahUKEwj-5YK7k8yDAxUHg_0HHScECVAQ0pQJegQIDRAB&biw=1242&bih=552&dpr=1.1
https://travelking.cz/blog/gastronomicky-bedeker-co-ochutnat-v-madarsku
And forgive your advantage of serving in the army here or there -I get into the car and in less than half a day I am on the front line of warring states where I can die directly in battle ( hey, you don't have anything?, that's an advantage huh? )😥
So what is colorful and diverse - or is it better to lie on the couch on an island in the ocean?
Ivan