The view looks to the SW. The W pk of Olympus is at upper center.

1:50,000 Topographic Map

Diodorus Siculus, Library of History 4. 11. 3 (trans. Oldfather) (Greek historian C1st B.C.) :

"The first Labour which Herakles undertook was the slaying of the Lion in Nemea. This was a beast of
enormous size, which could not be wounded by iron, or bronze or stone and required the
compulsion of the human hand for his subduing. It passed the larger part of its time between
Mykenai and Nemea, in the neighbourhood of a mountain which was called Tretos (Perforated) from a
peculiarity which it possessed; for it had a cleft at its base which extended clean through it and
in which the beast was accustomed to lurk. Herakles came to the region and attacked the
lion, and when the beast retreated into the cleft, after closing up the other opening he
followed in after it and grappled with it, and winding his arms about its neck choked it to
death. The skin of the lion he put about himself, and since he could cover his whole body with
it because of its great size, he had in it a protection against the perils that were to follow."