Founded in 1533 as a center of the Spanish empire, Cartagena developed into a sea of colors and a UNESCO World Heritage site within the colonial walled city. City tours–by car, foot, or even horse-drawn cart–take visitors through the cobbled streets and to the famous San Felipe fortress. Focused tours shine light on the multi-cultural worlds of local gastronomy or music, or the life of locally born author Gabriel Garcia Marquez. Nearby La Popa hill offers views of the old city, the harbor, and the 17th-century Santa Cruz monastery. Taking a cooking class or visiting a gold museum reveals the city's heritage, a mix of African, European colonizer, and Native American. At night, the streets of the hot and humid city fill with markets, traditional dances, and revelers spilling out of bustling nightclubs. For those who want to escape, a short boat tour brings travelers to Barú and Playa Blanca, where the white beaches and crystalline water are pure Caribbean paradise. A little further and travelers reach the Rosario Islands, a national park featuring one of the most important coral reefs in the country. To the northwest of Cartagena, the renowned El Totumo mud volcano allows locals and travelers to enjoy therapeutic massages and the natural healing properties of mud baths.