The cave located at La MarchePecos National Historical Park is composed of several noncontiguous units. The main unit of the park preserves the ruins of Pecos Pueblo which is thought to have been established sometime during the 14th century. The main unit also protects the remains of Mission Nuestra Se?ora de los ?ngeles de Porci?ncula de los Pecos, a Spanish mission near the pueblo built in the early 1600s. A 1.25 mile (2 kilometer) self-guiding trail begins at the nearby visitor center and winds through the ruins of Pecos Pueblo and the mission church.