Castellots de Tanca, in L’Espluga of L’Obac

Castellots de Tanca, in the range of L’Espluga from L’Obac (picture), Castellsapera (= castle of stone) and the ridge of Emprius display the edged pattern of relief that results from the oligomictic limestone conglomerates, in contrast with the round shapes that result from the polimictic conglomerates that stand for the majority in Natural Park of Sant Llorenç del Munt i serra de L’Obac and make the smooth summits of Montcau and La Pola.
Several routes climb the Castellots de Tanca. One natural tunnel crosses through the inside in its west stretch. There is also the natural shelter known as Quarto de Reixa in the basement of south side of Castellots de Tanca.
The range of L’Espluga branches from main range of L’Obac just in pass of Tanca, north from La Pola, to extend perpendicular towards the west until the hollow sot de Matarrodona. The whole range of L’Espluga belongs to municipality of Mura (Bages). Nevertheless Castellsapera, despite it belongs to the district of Vallès Occidental, and Els Emprius are better seen from Manresa and its neighbourhood because they align north-south than Castellots de Tanca that faces its bowsprit. [photo Jordi Badia]

See the article Conglomerat, in Catalan, by Jordi Badia.