What has happened to good old printed maps and MK I eyeball??
The Algarve is a rectangle running east to west, +- 160km wide East to West and +- 40km North to South.
Going West, 99% of the time one will usually hit the West Coast and fall into the sea!
Going South, the same will eventually happen
Going East, one will eventually fall into the Guadiana River on the Spanish border!
Going North can be a bit of a problem but one knows where one has arrived in the Alentejo by the "Oh, Aargh" deportment of the local yokels and the presence of a lot of sheep, goats and pigs
.....Its a bit like this......
Finally, be aware that our friends at Google Maps, Tom-Tom etc have been so busy recently assisting the NSA that they have conveniently forgotten to update satellite photos and maps for the Algarve!