On a rainy afternoon in Sol Madrid, one great option is to visit one of the many museums in the area. The Prado Museum, for example, is home to an extensive collection of European art, including works by renowned artists such as Goya, Velázquez, and El Greco. You can spend hours exploring the museum's galleries, admiring masterpieces from different periods and styles. Another option is the Reina Sofia Museum, which focuses on contemporary art, including the famous painting 'Guernica' by Picasso. These museums offer a perfect opportunity to immerse yourself in art and culture while staying dry.