Usually, I travel to Greece every year and this place seems to be perfect for any kind of vacation. You can find there everything you need and you can rest assured you won't be bored. As for nature, it's stunning and incredible. Also, here is a good list of destinations for travel, if you aren't sure where you want to go, just check out this article https://travelsites.com/blog/10-best-destinations-for-family-travel/
