I believe that this must be the question I answer more often in this context.
Of course the answer will always depend on who is asking, not everyone enjoy doing the same things.
Not only will depend on individual preferences but also depends on the time and money you have available to spend in this country.
My reply could be very different for those who want to come to Portugal for walking vacations of the response to those who want to come to Portugal to spend some time on the beach or visit museums.
However, I will try to simplify the idea and try to draw a plan to the visitor who wants to come to Portugal have active vacation but not necessarily for walking in the countryside. Will be a plan for a visitor who values visit areas with some History, who values tasting the cuisine and local wines and is also aware of the cultural issues.
I will also consider that this visitor prefers to see the sites in a more relaxing way rather than jumping from site to site in a frenetic ... more quality instead of quantity.
In relation to the time I will consider two possibilities: 7 days and 14 days.
For any of the options I find it fascinating to do the trip from North to South, in which the city of arrival will be Porto and Lisbon the departure city where there are more air connections with the rest of the world.
7 days: 2-Porto; 1-Guimarães; 1-Fátima/Óbidos; 2-Lisbon; 1-Sintra/Cascais
14 days: 2-Porto; 1-Guimarães; 1-Viana do Castelo; 1-Pinhão (Douro Valley); 2-Coimbra/Fatima/Óbidos; 3-Lisbon; 2-Évora and surroundings; 1-Sintra/Cascais; 1-Setúbal/Tróia/Arrábida
Each of these sites has a remarkable History, different customs and so typical gastronomy and wines to accompany and I will write about these places on this blog.
Join me to Portugal. I'll be glad to customize a tour for you.