The Tagus Panoramic Trail practically always runs along the right bank of the Tagus, between Vila Nova da Barquinha and Foz do Zêzere, in Constância. It includes the Almorol Trail and the Constância Trail.
Pedestrian trail, but that can be done by bicycle (MTB recommended). In rainy weather it can be difficult to do. Depending on the degree of experience, in some small sections you may have to dismount and push the bike.
This famous templar castle is on a little island with a very commanding position and to visit you have to book a short boat ride. The castle itself is small but very impressive and exceptionally well preserved.