Whilst you're in Dubrovnik, a variety of tours are available in neighbouring countries. I opted for the Bosnia and Herzegovina Day Trip from Dubrovnik including Medjugorje and Mostar - several friends of mine had mentioned Mostar to me before I began my travels, and sending a postcard from Medjugorje to my Nan would definitely brighten up her day.
The day started pretty early, I was the first pick up at 7.10am, by the time we'd gone round to all the other hotels it was approx 8am as we headed across the main bridge in Dubrovnik and stopped for a photo opportunity.