The ancient town of Lagos is filled with restaurants, bars, and shops. The walls of the old fort are at one entrance to the town.
This was the town from which the first Portuguese maritime expeditions embarked. Prince Henry the Navigator's school was located in Sagres and the ships and navigators left from Lagos' deep harbor to find new lands.
Walking through the old town, you have many restaurants that serve a variety of very fresh seafood, and traditional Portuguese dishes.
After a leisurely lunch, wander around and do some shopping. The shops carry cork products so popular of late in Portugal ( handbags, purses, belts, etc. ). Many shops offer linens that are beautifully finished. There are souvenir shops, and clothing shops.
Many kiosks are located in the different squares in town. Since the Algarve is so close to Africa there are Africans offering African textiles at their kiosks. The products are unusual.
You may now be thirsty and there are bars to stop at and sit out in the open air to enjoy a drink.
Don't neglect the various sights such as the old fort, the churches, the museum, or the marina across the main road.
There is plenty of parking in an underground lot.
Lagos is very safe at night even though it is a city. Just take the usual precautions. I have never had a problem there. I just watch myself.
If you can, visit Lagos. It is a favorite of mine.
One friend of mine who visited told me if she could, she would live In Lagos, Portugal.