The borough is in the southeastern part of the city and has an identity that is separate from the historic center of Mexico City, due to its historic separation from that city during most of its history. Xochimilco is best known for its canals, which are left from what was an extensive lake and canal system that connected most of the settlements of the Valley of Mexico. These canals, along with artificial islands called chinampas, attract tourists and other city residents to ride on colorful gondola-like boats called “trajineras” around the 170 km (110 mi) of canals.