Contributor PJF Drone created this excellent drone video of an important reservoir lake in west central Spain. It's called the Entrepeñas Reservoir, and it's located on the Tagus River in the Guadalajara Province. The surface area of the reservoir covers nearly 40 square km (just over 12 square mi.), making it one of the larger lakes in the Castile-La Mancha region. Together with other reservoirs in the vicinity, the Entrepeñas Reservoir forms part of what is sometimes called the Sea of Castile.