At its peak during the 15th century, approximately 1,000 to 1,600 people lived in or just outside the walled city of Tulum. Today the only inhabitants are hundreds of iguanas like this Mexican spiny tail. The less than attractive Ctenosaura Pectinata can grow up to 4 ½ feet. They spend most of their day basking in the sun or hiding in sparse vegetation. However, when they want to move, they can reach a speed above 20 miles per hour.
