Begin your first day in Madrid at the Royal Palace, the official residence of the Spanish royal family. This stunning palace dates back to the 16th century and boasts a vast collection of art and artefacts from different eras. It's advisable to book your tickets online beforehand. After the palace, take a stroll through the Retiro Park, one of the most beautiful green spaces in Madrid. The park contains peaceful lakes and gardens, as well as the famous Crystal Palace and Rose Garden.
Begin your day at the world-renowned Prado Museum, which houses an impressive collection of European art, including works by Velázquez, Goya and El Greco. It's advisable to book your tickets beforehand, to avoid long queues. After the museum, head to the lively Puerta del Sol, the heart of Madrid. You can relax here, take a walk around, shop or dine at many of the restaurants in the area.
On your third and final day, head to the iconic Plaza Mayor, Madrid's central square since the 17th century. You can see many of the city's unique historic buildings, shop and eat local food. After that, visit the Temple of Debod, one of Madrid's best-kept secrets. This Egyptian temple dates back to the 2nd century BC and was donated to Spain by Egypt in the 20th century. It's a perfect spot to watch the sunset from.
If you have more time, you can explore other neighbourhoods, such as Gran Via and La Latina and visit the modern art centre Reina Sofia. Also, consider visiting the flamenco tablaos for a great night of music and dance. If you have less time, consider either skipping the Retiro Park, or just visiting it briefly.