More lens advice

[nickcowen]

My girlfriend has won a holiday to a private island in the seychelles. So as I'm probably new going to go there again in my life I wanna make the most of it. Would like sugestions on what lens would be best to capture the sights. I have a Sony a390 with 18-70mm kit lens. It could be 80 but I'm pretty sure of the top of my head it's 70.