Tejera Negra is a beech forest located in Cantalojas, in the northwestern corner of the province of Guadalajara.

It is part of the Ayllón massif, at the eastern end of the Central System. It is one of the southernmost beech forests in Europe.

In 1974 the Tejera Negra beech forest was declared a natural site of national interest and in 1978 it was declared a natural park, which was expanded in 1987. Since the creation of the Sierra Norte de Guadalajara natural park, on March 22, 2011, it was integrated within this, for which its previous declaration of natural park was repealed.

In 2017, along with other beech forests in Spain and Europe, it was declared a World Heritage Site by Unesco as an extension of the primary beech forests of the Carpathians and other regions of Europe.

The "Natural Park of Hayedo de Tejera Negra" receives its main name from Hayedo and its complementary name, "Tejera Negra", from the neighboring valley on the west, the Sorbe river basin, where a smaller ravine appears on the topographic maps, exposed to the north, with the name of Tejera Negra.

Summers are mild and cool and winters are very harsh, with snow for two or three months. Temperatures vary between - 14º and 23º.