If you're looking for a unique experience on a rainy afternoon in Sol Madrid, consider exploring the city's indoor markets. Mercado de San Miguel, for instance, is a popular food market where you can find a wide range of Spanish delicacies, including tapas, seafood, and pastries. The market's vibrant atmosphere and diverse food offerings make it a great place to indulge in some culinary delights. Another option is Mercado de San Antón, which offers a mix of food stalls, gourmet shops, and rooftop terraces. These indoor markets provide a fantastic opportunity to discover local flavors and enjoy a gastronomic adventure.