Other things to consider for your trip are the sights or activities you would like to do see or do while you are away. Do you want to go to somewhere historic like Rome or to a resort hotel in Mexico that you don't have to leave as you have everything you need within the resort?
Landscape is also a factor. There are cities, countryside towns to look into, would you like a beach or some scenic mountains?
Who are you taking with you? Will there be things for the children to do? Will there be too many children there as it's family friendly and it's a romantic week you are looking for?
Budget is also an issue. Look at how far you think you will be able to go and work from there. You never know, some price comparison sites could surprise you and you may be able to go further than you originally thought.
Once you know how much you want to spend and have an idea of what kind of climate you would like. Go and talk to a travel agent or get some brochures to have a look through. This way you can have a look at what is out there that will suit all of your requirements.
Don't forget, recommendations and experiences from friends and relatives are priceless when look at where to go on holiday.