Is it possible to see Mycenae and Argos in a single day trip by bus from Nafplio?
As far as I know, there is one bus from Nafplio to Mycenae every morning which returns about three hours later giving sufficient time to see the site. There are no buses between Mycenae and Argos but I’ve never seen any reason to go there. It’s the sort of place you pass through on the way to somewhere else.
Argos has one very interesting fact; it is one of the places in the world that has had the longest uninterrupted human settlement, since 5000 BC , it is worth stopping there and look around reflecting on this, but i would not go out of way to do that either :)
There is a lot more to see in Mycenae as there's been a lot archeological work done there.
It's very impressive and you could spend hours there wandering around. Nice museum and some fantastic Tholos Tombs within walking distance of the main site.
I haven't been to Argos but from what I've heard doesn't have as much to offer a Mycenea.
An option to Argos could be Nemea with some wonderful "ruins"
You could do both but Mycenea and Nemea in one day especially if you have a car but get an early start.