The Tour des Collines du Perche (TCP) is a 8 stage loop in the regions of Centre Val de Loir and Normandie, it is indicated via an orange blazon (see photo above).  Several websites give descriptions of the route, lodging possibilities, the possibility to buy the guide book and the GPX files. (one site indicated below)

Randonnée itinérante - Site de letourdescollinesduperche ! (jimdofree.com)

This route is the new version of an established FKT route at Old Rag Mountain, VA. Parking has changed and new trails have been been formed due to the crazy popularity of this area, and the park service has discouraged use of the old access trail to the start of the current FKT route. Due to these changes it seems to make sense that the old FKT route be retired and a new route be established that starts and finishes at the new parking area. 

Höhenluft schnappen auf dem Löwenpfad "Höhenrunde" in Bad Ditzenbach. Eine Runde mit jeder Menge Ausblicke ins Obere Filstal - wer den Albtrauf liebt, kommt hier voll und ganz auf seine Kosten. Einen Abstecher zur Ruine Hiltenburg am Schlossberg sollte unbedingt eingeplant werden, denn sie zählt zu einer der am besten erhaltenen Helfensteiner-Burgen im Kreis.

Auf die Spuren des Löwen können Sie sich im Landkreis Göppingen begeben: Die Löwenpfade stehen für Qualitätsanspruch und locken mit eindrucksvollen Ausblicken, abwechslungsreichen Naturlandschaften und geheimnisvollen Orten.

Viele wunderbare Aussichten und bemerkenswerte historische Stätten zeichnen diesen zertifizierten Premiumweg aus.

The Grebbelinie path crosses many historical landmarks. It was a well-known Dutch defense line. It was build around approximately 1750 but also utilized in WWII, also by German soldiers. Along the route there are many bunkers, cemeteries and memorial signs. A part of the route goes through military trenches. There is a booklet available about the route. The (original) route goes from Rhenen to Spakenburg. At a later stage, a few extra sections were added (see Wandelgids Grebbeliniepad,  Rhenen-Bunschoten-Spakenburg). The route is described in great detail on: