Burgau is not a town! It is a small old fishing village with two or three streets and is likely to be very busy during the period you are in Portugal. The same may be said of the village of Salema 5km down the coast.
The Southern Region of Portugal, including he Algarve region, and the Southern Alentejo region,boast very few towns with traditional architecture and "quaint streets". This area was the last region of Potrugal to develop.
The Southern towns with "traditional architecture" and "quaint streets" are few and far between and include Lagos, Tavira, Monchique, Silves, Tavira, Mertola, Alcoutim, Beja, Serpa, Evora. There are many lovel villages but throughout the region but these do not generally boast "traditional architecture".
The Algarve and Western Alentejo seaboard has a wonderful coastline but does not boast many towns with an historical coastline.
Again, I must reiterate that the whole coast, like around Burgau, is likely to be heaving during the period you intend to visit. In the case of Burgau, this is likely to be exacerbated by the volume of day trippers visiting from the Spanish Cities of Huelva and Sevilla.
I think it is quite possible to have a very enjoyabable visit to Portugal without visiting the South. The historic original regions of Portugal lie to the North around Guimarães and Porto.
See this wikipedia article for more: http://bit.ly/wikihistoryofportugal
