Inside the Saint Augustine Lighthouse in North Florida, there was a wonderful spiral staircase. This one was massive with an unusual open center and was made of cast iron. It was a feat of engineering and design because it gradually got smaller as it went up.
You updated us well. A good image here. Thanks
You are a keen observer Thanks for the beautiful photo
This reminds me of the staircase inside the Monument in London, which was built to commemorate the Great Fire of London in 1666 and was designed by Sir Christopher Wren. However, this was built from stone rather than iron! I have a photo that is very similar to the one from your lighthouse.