Twice a day the River Thames levels can change up to 7 metres! At low tides, you can walk down steps and get onto the foreshore in many places and look around on the 'beach' for any interesting objects. It is known as mudlarking and in the 19th century, it was a daily way of life for people trying to make money from what they found. I have been mudlarking on the river 4 times now and have now got quite a collection. To dig you need to buy a permit but there is enough on the surface to mean you don't have to dig to find things. There are so many ceramic pieces, it seems people used to just throw their plates into the river after every meal.
The jewellery was all found together in a hoard just under Blackfriars Bridge and was just sitting on the mud. I think it must have been a quick disposing of evidence from a robber.. it's mainly tacky fake jewels but sitting amongst ceramics, it's quite impressive.
There are also lots of old clay pipes which are generally broken and seem to be the 17th century equivalent of cigarettes.