Saturn's largest moon, Titan, does have some liquid seas, near its north pole — the only other stable liquid seas in the entire solar system besides Earth. But don't change into your bathing suit just yet, as these seas are filled with hydrocarbons, primarily liquid methane or ethane. The largest of these seas which has been definitively confirmed is about the size of Lake Superior. One possible sea is several times larger, approaching the size of the Caspian sea. Drainage channels and other telltale geographic features have been mapped as well.
If Titan's atmosphere had oxygen, a single match could could ignite an area hundreds or even thousands of square miles large, as hydrocarbons are flammable. Luckily, Titan's atmosphere is 99.8% nitrogen. Titan is the only other rocky body in the solar system with an atmosphere composed of more than a few trace gases. The atmosphere is so thick, and the gravity so low, that a human being with wings strapped to their arms would be able to fly through it with little effort.
Since it was discovered in 1655, Titan has largely been a mystery, as it is covered in thick clouds like the planet Venus. However, a recent space probe mission, Cassini-Huygens, has given us a tremendous amount of new information about this alien world, confirming the existence of Titan's hydrocarbon lakes as recently as January 2007. Cassini, the orbiter, dropped the probe Huygens down to Titan's surface on 14 January 2005.
Dozens of flybys of the Cassini orbiter have confirmed the existence of Titan's long-hypothesized hydrocarbon lakes, along with geographic features such as a well-defined coastline, islands, drainage channels, and nearby mountains. Cassini-Huygens is an international collaboration between NASA, the European Space Agency and the Italian Space Agency. The probe's trip to Saturn took just under seven years, and it is the first artificial satellite to orbit Saturn, but the fourth to visit it. The total cost of the project was $3.26 billion US Dollars.