The origin of Leiria, which is located approximately at the end of the first third of the course of the river Lis, is connected to the dome of ophitic dolerite rocks. On it the castle was built and under the wind protective topography the hills provide, its historic centre thrived. The first human settlements in the Lis Valley, whose slopes are mainly sandy, can be glimpsed through the multiple archaeological open-air sites, located on the banks of the former water courses. In these banks one could find gravel deposits made of quartz, quartzite and flint pebbles, that would be used to make tools for hunting and other activities. The conditions favourable to the presence of the first men also justify that our kind have settled here. The Lapedo child fossil, that allows us to discuss the genetic connections between sapiens and neanderthalensis, is a very good example of just that.
