Río Lobos Trail, along the Canyon Floor

The river trail, the PR-SO-BU-65, runs the whole canyon beside the river Lobos: 25 km one way between the Fuente Engómez entrance, in Ucero (Soria), and Hontoria del Pinar (Burgos), beside its Roman bridge. Patrimonio Natural rates it medium difficulty, because although the canyon floor is almost flat, the trail crosses the river many times and adds up to about 592 m of cumulative ascent between 961 and 1,051 m of altitude. Almost nobody does it in one go: the usual thing is to choose an out-and-back section, on foot or by bike.

The most usual sections

Fuente Engómez – San Bartolomé hermitage. It is the shortest and the busiest. It starts from the junction of the SO-920 with the canyon entrance, beside the Fuente Engómez recreation area, passes the Valdecea pool at around km 2.6 and reaches the San Bartolomé hermitage at km 3.7. With children, it is the one that makes sense.

Hermitage – Siete Ojos bridge. From the hermitage, the trail continues upriver past the Presón cave (km 4.5), the Cueva Negra (km 7.1) and the Peña Palomera viewpoint (km 9) to the Siete Ojos (Seven Eyes) bridge, at km 12.2. The bridge can also be reached by car, parking on the SO-934 between San Leonardo de Yagüe and Santa María de las Hoyas, and from there you can go downriver towards the hermitage. On this stretch are the Colmenas de los Frailes. The park leaflet warns that the crossing between the Siete Ojos and the hermitage has some difficulty.

Siete Ojos – Hontoria del Pinar. The second half, towards Burgos and the least visited, passes the La Canaleja spring (km 13.7), a resin tappers' hut (km 21.8) and the Los Agualinos spring (km 23.2) before reaching Hontoria. Between Agualinos and the Siete Ojos are the canyon's springs, the biggest being Las Raideras.

Before setting out

Check the state of the river. With heavy rain, the fords become very difficult or impossible, and with the river in flood some parts of the path get wet. Ask at the Park House in Ucero, on 975 363 564 or at [email protected]. Patrimonio Natural has the PDF sheet and the track on its website.

Bring water from the start: there are fountains at some points, but they are untreated, and at the bottom of the canyon there are no bars or shops. In heat, a cap; in the cold, beware of ice in the shaded areas. Good footwear, because you will tread on stone and cross the river.

Logistics

As it is one-way, to do it whole you need two cars or someone to pick you up: there is no useful public transport between the ends. The car parks on the canyon track, Fuente Engómez free and Cueva Fría and Valdecea paid, are on the page for the canyon car parks. From Hontoria del Pinar, Pedrete Guiados runs a guided walk through the Burgos stretch.