Deep was the cave, and downwards as it went
From the wide mouth, a rocky, rough descent:
And here the' access a gloomy grove defends:
And there the unnavigable lake extends,
O'er whose unhappy waters, void of light,
No bird presumes to steer his airy flight:
From hence the Grecian bards their legends make,
And give the name Avernus to the lake.

Dryden.