We walked through some neighborhoods to the Boca do Inferno, translated as ‘mouth/opening/entrance of hell’
It is a natural stone cave that collapsed and created an arch.
The famous British Alexander Crowley spiritualist/medium/charlatan staged his own suicide there. Read more about it here:
https://www.theportugalnews.com/news/2021-01-22/boca-do-inferno-in-cascais/57855
