Sagres is located on Portugal's southernmost tip. The town itself isn't much to look at, but many people trek out this way from Lagos (by bus or car) to visit Cabo de São Vicente, which was once thought to be the end of the world. Looking out from the isolated, craggy cliffs, there really is a whole lotta nothing, so you can understand why one may have thought as such. The cape is about 6 kilometres from the town centre. Surfers are also attracted to this part of the world for the decent surf breaks.
You might recognise the word Sagres from beer bottles around Portugal, as it's one of the country's two major beer brands (the other being Super Bock). Despite the name, Sagres beer is actually made near Lisbon.