This plan or picture map of Great Yarmouth is from the reign of Elizabeth I. According to the Norfolk Record Office (pdf),
It shows the town’s defences at the time of the Spanish Armada in 1588. Its depiction of the town’s layout is not wholly accurate (the streets, for example, were laid out in a grid-like pattern), but the marketplace and St Nicholas’s Church are easily identifiable.
This image is taken from the British Library site which gives c.1585 as the date. Source: British Library.
What are people with the large 'wheel' doing (blue number 1)?
What are the structures (blue numbers 2)? I’m thinking that they are fish traps but can’t find anything to confirm this.
Note: In case anyone is curious, the ship with the flag with black and white horizontal stripes would appear to be from the Belgian commune of Waimes