Sweden is BEAUTIFUL! I visited in August 2016. This was my first overseas travel. Rich culture, beautiful architecture, long vast history, and wonderful food. Island hopping isnt just a tropical thing! Along the coast There are plenty of little islands to visit.
Inland is easy to visit as the train system is very efficient here. Make sure to take a moment for "Fika" or coffee/tea break. Unlike the USA, a coffee break here is a moment to relax, chat, not just caffeinate, but truly refresh yourself. Not just a time to caffeinate and go like I am used to.