San Ildefonso is a town located in the province of Segovia, Spain. It is known for its beautiful architecture, including the stunning Royal Palace of La Granja de San Ildefonso, which was built in the 18th century. The town is surrounded by the Sierra de Guadarrama mountains, making it a popular destination for outdoor activities. The town is also famous for its historical significance, particularly its connection to the Spanish monarchy. San Ildefonso hosts various cultural events throughout the year, attracting visitors interested in its rich heritage and scenic landscapes. The area is a UNESCO World Heritage site, recognized for its cultural importance.