Although the Peninsula has a long and interesting history some of the land it seems is fairly new!
Yet more research resulted in finding the picture (to the left) and a few paragraphs about Landguard Point. The book is The Geology of the Country around Felixstowe and Ipswich by P G Boswell. In the last pages of this book is a paragraph about Landguard Point and how the size and shape of the Peninsula was affected by the building of the Jetty on the Point.
Sand and shingle being moved down the coastline by longshore drift was now (and still is) getting caught by the Jetty rather than adding to the sand/shingle bar that had being forming across the entrance to the harbour and preventing Class 1 shipping from accessing the ports of Harwich and Ipswich. Additionally the river currents were now able to scour away said bar.
This picture above was taken in 1914, 48 years after the Jetty was finished. On the left of the picture is the Landguard Lighthouse, built in 1861 and accidently burnt down in 1925. Just beyond that is the bungalow, the extension housing my office is yet to be built. Beyond that the 'hill' is Right Battery decades before the WWII gun emplacements were built. Mr Boswell estimates that this build up caused by the Jetty became 25 acres of new land made up of around one million tons of shingle. He used the people stood in this photo to demonstrate the high tide line that existed pre-Jetty in the early 1880's and the land to the right
of them is all new.
The second photo on this page is taken today from approximately the same place, then in the following two photos i've tried to point out the changes.