The second-highest mountain range in Portugal, Serra da Estrela is a year-long tourist attraction and a popular place for skiers of all levels. It also has the highest altitude in the country and is covered in snow all winter long.
Travel with an experienced guide/driver to the mountains from Lisbon. Along the way, stop at the nearby Bread Museum, a local cheese factory, the pond of Lagoa Comprida and the tower of Serra da Estrela.
Then spend at least an hour in the ski park, trying out the many trails or just playing in the snow. If visiting in the summer months, use the chairlift to get up the mountain and explore its natural beauty. The company provides the sleigh for you to have a unified experience. Your guide and driver will return you to Lisbon at the end of the day.