Visit the Salton Sea
The Salton Sea is a 340 square mile body of water about 50 miles south of Palm Springs. It's shallow for its size, measuring about 43 feet deep at its deepest point. The lake or sea was essentially created by accident in 1905 when floodwaters from the Colorado River overwhelmed and breached some irrigation canals, causing water from the Colorado to be diverted into the ancient dry lakebed. The river water continued to fill the depression for over 2 years before it was finally fixed.
Instead of evaporating away, farmers in the area continued to let excess water runoff into the lake. In the 1950's and 60's, developers got the idea that it could become a leisure and resort destination for nearby Los Angeles. All kinds of development took place along the lake including yacht clubs, hotels, and entire communities of homes.
But by the 70's the stagnant lake started to show signs of pollution and contamination. Massive fish die-offs started occurring as fertilizer and salt concentrations increased. In later years, a series of particularly rainy years actually raised the lake level so much that it flooded out many of the buildings that had been built along its shores.
Today, visitors can see some of the remaining abandoned buildings in places like Bombay Beach.