The correct answer to this open question is the following.
Unfortunately, you did not attach the options for this question. Without the specific options, we can answer so many different things according to our knowledge and experience on this topic.
We can help by sharing our own perspectives.
To know where the cities and tourist destinations of a country are, you need a map to know the destinations and where the main attractions are located.
Another good option could be:
To know where the cities and tourist destinations of a country are, you need to search on the web where the main touristic places and how to get there, as well as the best packages and transportation prices.
One way or the other, the important thing is that previously have enough information in order to make a smart decision on where to go and what to visit, and better plan your vacation, knowing how much you can spend to fully enjoy the country's touristic attractions.