BBC Radio Devon's Gordon Sparks has been to Plymouth's camera obscura at Seymour House at Mount Wise, which is believed to be the only one in the world which is viewed from underground. Gordon took all the photographs in this gallery.
A camera obscura is an optical device which projects an image of its surroundings onto a screen. The majority are sited on high buildings. The Seymour House version was funded by the DRC Partnership.
The lens has been designed specifically for the Plymouth location, with a long focal length in order to give detailed views of the shipping and the buildings of interest in the city.
Jo McCaren is the teacher on site and operates the camera obscura by using ropes. The whole thing was her idea. "It makes people look at Devonport in another way," she said.
The camera obscura can be rotated around the horizon, this movement is called azimuth - the image can be made to scan up and down to show objects near and far.
The camera obscura is open to the public and groups on Monday afternoons for 30-minute sessions, which have to be booked in advance. Log on to www.tamarebp.org.uk for information on how to book.
"It's like when you take a picture and have it blown up," said Gordon. "It's so clear - everyone should come and see it, it really is amazing."
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