John O'Groats, in Scotland, is almost the northern tip of the mainland of Britain. It's named after a Dutch trader, Jan de Groot, who started the first ferry route out to the Orkney Islands. (Technically, Dunnet Head a few miles away is the actual northernmost point, but no one much seems to care.) Both look out toward the Orkneys. The harbour and the Last House museum (admission to which is apparently free, as it's not too big of a tourist site), and rocky beaches with lighthouses and ships are worth seeing, though the actually town is described as full of kitschy shops. And it's the common ending point for people who have walked or cycled the north-south length of the island, starting at Land's End in England.

Sources:
www.sigma96.demon.co.uk/links/johnogrts.htm
http://www.writersite.co.uk/Travel/Scotland/Groats.htm
http://www.frii.com/~phouka/travel/other/johngroats/johngroats.html