Portugal is a favourite of mine and I would recommend that you make a trip there.
The best way to travel in Portugal is to either go north to south or in reverse. There are many flights to Porto (North) and Faro (South), you can of course fly to Lisbon however you may have to back track if you want to see everything. When we did this trip we started in Porto and ended in Faro.
Porto is famous for the wine Port. This is a beautiful little city, you will be stopping at every corner to take a photo. Porto has colourful churches with tile pictures over the outside walls. Once you reach the river there are wonderful bridges that you can cross and view the old town that lines the river. You can take a tour through a Port wine cellar on the south side of the river. Not into drinking? Take a boat ride down the river.
At night you can find many spots along the river in the old town, the place comes alive at night with everyone coming out once it starts to cool down. After Porto you can head to Lisbon, this takes abit over 3 hours by train.
Lisbon is the capital of Portugal, so as expected it is a very big city. This is a city where the hop on hop off bus makes sense. The bus will give you facts about the city and also gets you out to Belém Tower and Jerónimos Monastery.
Once you have got your bearing in Lisbon you want to spend a day in Sintra, this is a mountain range with palaces all over. You can get a train to Sintra, from there there are many options from the station to the different palaces. We decided to walk, be aware you need to be fit to do this and ideally not in the middle of the day when the sun is at its peak. We visited the Palace of Pena, this Palace is a show stopper. We also visited Castelo dos Mouros. If you got a ride up the hill you would be able to visit more places however the two places were enough for us with the walk back down still to be completed.
In Lisbon you must grab a portuguese custard tart treat, we were lucky enough to be given some from our AirBnB host. After Lisbon we headed to Lagos
Lagos is a coastal town on the southern coast of Portugal. This is a 4 hour ride on the train from Lisbon. Lagos has many picturesque beaches with cliffs surrounding the beaches. Lagos also has a nightlife, when we were there they were running an event where different bars had a $2 drink and tapa offer, we managed to get around many bars in the night treating ourselves to many different tastes. However once you are south the key is relaxation so grab a towel and chill.
From Lagos you can always hop onto another beach spot like Albufeira before flying home from Faros.