Good Nikon lens for Italy?

I'm going to italy and i currently own a nikon d3100 with a 18-55 and a 55 to 300. I don't want to be carrying both lens around. Is there a in between lens. No more than 3 to 4 hundred dollars. Thanks! Btw i will be in rome Florence tuscany and venice! Thats where ill take pictures!

I know this is out of your budget, but the Tamron 18-270 ($650) would be a great all-around lens. I recommend that you just use the lenses you already have.