Nordkapp is often attributed as the northernmost point in continental Europe (though Wikipedia has a few remarks about that), Tarifa is the southernmost point.  To run between them is roughly 5300+ km.

The GR221 is a 135km route across Mallorca, from Port d'Andratx in the south west of Mallorca, all the way to Pollenca in the north east, following ancient cobbled paths through the Tramuntana mountain range. The hike generally takes eight days and there are hostels located at the end of each stage for hikers.

The "Berliner Höhenweg" is an alpine loop in Zillertal, Tirol, Austria. Due to the relative good infrastructure, but high difficulty (rugged rocks and mountains up to 3100m), the Berliner Höhenweg is one of the most desired FKT destinations in Austria for Trailrunners.

Start/End is Europahaus Mayrhofen. 

It is run anti-clockwise via the following Alpine Huts: Mayrhofen (633m) - Gamshütte (1921m) - Friesenberghaus (2498m) - Furtschaglhaus (2295m) - Berliner Hütte (2044m) - Greizer Hütte (2227m) - Kasseler Hütte (2278m) - Karl von Edel Hütte (2238m) - Mayrhofen (633m)

The Frankenwaldsteig is a 242km loop route in the Frankenwald of Bavaria.

John O'Groats to Land's End (JOGLE), or it's reverse route (Land's End to John O'Groats, LEJOG) connects the extreme tips of the island of Great Britain.  It's somewhere between 800 and 875 miles, depending on the route chosen.  The route has been done on foot and by other means at least since the 1870s, and records are kept for nearly every type of transportation imaginable including: