This document provides information about activities in Serra da Estrela, the highest mountain range in mainland Portugal. It describes tours of museums and villages in Seia located on the northwestern slope of Serra da Estrela. It also mentions hiking, skiing, snowboarding, and other outdoor activities that can be done in the Serra da Estrela Natural Park, especially between April and October. Additionally, it notes the crystal clear waters and thermal springs in the area that are suitable for bathing.