Looking for Honeymoon Location

I am getting married in the Spring, April to be exact. Me and my fiancee are from the United States and have traveled in our country but are looking for somewhere to go abroad. It will be our first time out of the country.

We are in our 20s and in good physical shape, so there should be very little that we would not be able to do as far as hiking, walking, swimming, that sort of stuff.

We get excited by so many places that we see that it is extremely hard to narrow our list. I personally would like to avoid some of the more popular areas such as London, Spain, and the usual western european US spots. We will be able to visit those later in life when it is not our honeymoon.

We thought about the possibility of going somewhere that was geographically interesting. Such as Montu Picchu, New Zealand, or Croatia.

I would love to be able to something that involved a train. We looked at some of the trains in India. I have heard that Americans are not well received there though and can be quite dangerous of us. Has anyone had any experience with this?

If anyone has ever had an outstanding trip that they would highly recommend please share.

Thank you guys very much.