Cascada del Aljibe is a nice double waterfall near the hamlet Matallana in the region Castilla la Mancha-Guadalajara, Spain.
From Matallana it is 1,6 kilometer walk to Cascada del Aljibe. From Matallana a trail runs to Puente de los Trillos. There you have to cross the river Jarama and the take an exit to the right to Pozas de Matallana.
I am not sure it is allowed to take the dust road from Roblelacasa to Matalana. Otherwise you can start in Roblelacasa and make a roundtrip to Cascada del Aljibe. More information about this hike on Wikiloc.