Traces of an ancient road in a lake

Eight hundred years of settlement history with land reforms, epidemics and repeated wars are preserved in the sediments of Lake Czechowskie in Poland. The key role was played by the so-called Margrave's Road, the 'Via Marchionis', between the Prussian heartland and the Teutonic Order's castle Marienburg (today Malbork in Poland). The road remained significant for centuries.

source https://www.sciencedaily.com/releases/2021/10/211022123819.htm