Which Nikon lense is best for my mediterranean cruise?

I have a Nikon D5000. I'm looking to buy an FX Zoom lense. I'm not sure which one though, and it would have to be inexpensive. I'm going to rome, so i need lenses for the tower of piza, the dome, and all around the mediterranean countries. I need a lense for buildings, beach, nature, that kind of stuff. Any ideas?

Added (1). Well, I'm 15, so not alot. Hopefully $200- $300 on ebay or craigslist.

Buying an FX zoom means that you are eventually going to be buying a full frame Nikon camera some day.

Actually, until you do that, the 18-200 mm is an excellent one lens solution for your trip.

What is your budget?

do you want an all in one? (look at the 18-200mm)

do you want high quality? (look at the 24-70mm f/2.8 and 70-200mm f/2.8)

edit;

there are not many lenses in that budget. You can look at the 55-200mm or 55-300mm lenses if you want telephoto zoom. You will still want to take your 18-55m lens with you

I'd get an 18-135mm or 18-200mm as an inexpensive all-in-one lens.

The lens being FX isn't important at this point.

I cruse extensively in the Caribbean, and I take a Nikon 18-200mm and Tokina 11-16mm on every cruise.

The 11-16mm is very useful for taking photos of the inside of ships, cathedrals, and so on.

But between the two lenses, it will cost you $1, 500.