Mars  is the fourth planet from the sun, and is significantly colder and smaller than Earth.
Foreigners (meaning Earthlings) should be aware that the gravity is much lower on Mars. Mars, being a planet, is huge, and it is unrealistic to expect to see all of Mars in a short period of time, although it is possible to view half of Mars through a telescope. Generally, areas along the equator are the most hospitable to Earthlings (at about -15 degrees celcius) as it is much warmer than the rest of Mars (the poles are colder than Yakutsk).
The Mars equatorial regions are the warmest part of the planet, as well as the most densly populated part of the planet. Most of the northern half of the planet is covered in ocean, and the southern part of the planet is almost entirely above sea level (except for the large Hellas sea and Argyre sea. Many places in the south part of the planet are uninhabitable.
The amount of gravity on Mars is significantly lower than Earths. Cities on Mars are built around this fact. unlike Earth, "bounding" is a common way of locomoting, and is very efficient. Inside most structures on Mars, gravity is artificially created for many reasons, mainly to keep muscles from atrophying and also to keep things tidey. Gyms are very important on Mars, as exercise is required in order to stay healthy with the low gravity. Gyms are a very popular spot for recreation.
All foreigners are required to obtain a visa before entering Mars, at the embassy of Mars in Antarctica. Be sure to make a personal trip to the embassy, or else your application will be rejected. If you arrive without a visa, be prepared for the Martian customs to fling you out into deep space. It will be very sad indeed.
WARNING: There are many things that you cannot bring into Mars, for the customs are even stricter than those in Australia and New Zealand, in order to protect the fragile eco-diversity of Mars. No fresh foods, pets, rotten foods, wooden, plastic, metals, oil-based, starch-based, cotton, polyester and China-made products are allowed beyond the customs. If any of the products are found, the death penalty is mandatory and you will be killed by Electric Chair in front of the entire planet on Planetary TV.
Mars' primary gateway is the Mount Olympus International Spaceport (which will be larger than the one planned in Dubai) in the city of Xanthe. (IATA: MARS). It is one of the worst spaceports in the universe, with many earthlings wondering why there are restrooms for 3 different genders.
Access to Mount Olympus International Spaceport is only by space travel, which takes several months from Earth. Be prepared for a very long flight, although most shuttle services are actually quite comfortable, and you can float yourself in the spacecraft all the way like all NASA people do on television. Great for kids. Several airlines or 'spacelines' are able to take you all the way to Mars:
NASA  operates flights once every 3 earth years. However, it has a very poor safety record (it is not allowed to enter the EU) with almost half of all spaceships ending up in flames.
Russian Federal Space Agency , one of the 'babyflots' founded as the Soviet Space Program dissolved together with USSR under Gorbachev. Its base is now in neighbouring Kazakhstan. I don't think they will operate any flights soon.
You can teleport to Mars straight away. However, the wormhole to Mars is presently (I think, for it's the CIA's secret) in Baghdad, Iraq, so probably that's why the Americans attacked - to control Mars!
"Bounding" is a common way of locomating outside of structures, and many Earthlings are suprised how fast and smoothely they can actually move. Remember to be careful not to bump into other "bounders," as this is rude and can cause injury. Large cities have excellent public transportation services, such as subways, monorails, and buses.
On the other hand, Mars boasts a very poor sector in aviation. Popular airlines include Mars Airlines, and flights from Xanthe to Nepenthes depart daily. Note that Mars Airlines has an even worse passenger record than Biman Bangladesh Airlines, for flights can be delayed up to 1 year, then forgotten about entirely. Then you will realise that you are scammed and your $15,000 is gone and you are left with many poor passengers who are trapped in the transit area. Realise that your money could have been better spent on a bribe to one of the officers to allow you for a hop in one of the chartered planes. NOTE: Wikitravel does not condone bribery.
Xanthe - By far the largest city of Mars, Xanthe (named for the region it is located) is in the nation Meridani, which was under Chinese rule until 2112. Xanthe is a very cosmopolitan city, and attracts the greatest number of tourists to Mars every year. The official language of Xanthe (and all of Meridani) is Chinese, although many other languages, especially English, are spoken due to the diversity of the city. Located on the Martian equator, the weather in Xanthe is very pleasant most of the time.
Nepenthes - Another popular tourist attraction on Mars. Nepenthes is famous for its nightlife and beach lifestyle. Located in the nation Elysium (which gained independence from United States of Europe in 2098), Nepenthes has mild weather. The languages spoken in Elysium are mainly English and Italian.
Hebes - The most populous of the Tempe nation (formerly American Republic of Temple), Hebes lays directly across the famous Valles Marineris from Xanthe. English is the most common language, as Tempe used to be under American rule. Hebes is renowned for its extremely "futuristic" city planning, including monorails and multiple city layers. Xanthe and Hebes, although of different Martian nations, are often called "the Twin Jewels of Mars" because of their close proximity to eachother.
Hellespontus - The southernmost of the large Martian cosmopoli, Hellespontus may be cold for many tourists seaking a more pleasant, relaxed environment. However, the city is indeed very hospitable. Often called "the Amsterdam of Mars" for its extremely liberal drug and prostitution laws, Hellespontus attracts many visitors looking for a more "adventerous" vacation. Hellespontus is located in the nation Noachis, which was a Russian territory until 2090. It is a costal city, located on the Hellas sea (the largest body of water in southern Mars). Gambling is a major industry in Hellespontus, and all cities in Noachis.
Tharsis - Another major city in Tempe, Tharsis is a highly modern and sophisticated city located a short distance from Hebes. While often overlooked, this city provides many tourist oppurtunities.
Apollinaris - Another equatorial resort city of Elysium. Italian is the most commonly spoken language.
Lycus - Although not a large city, Lycus is famous for its location: the base of the famous Olympus Mons, an important Martian landmark. Located in western Tempe Many tourists from around Mars and even Earth frequent the city for its renowned skiing oppurtunities. Being relatively high north gives Lycus a colder temperature.
Lubenstaraguntenfeischmidt - A colony of Utenstovudrakustaavendagentutenzania, It was a present from the president of The Republic of Uuuuuuuuuuud. Now it is a popular tourist getaway for people looking for three things: chocolate, chocolate, and more chocolate! In 2101, a giant Snickers truck was in an intergalactic highway when suddenly, a Twix truck crashed into it. Then, the trucks exploded so dynamicaly, that all the chocolate rained down on Lubenstaraguntenfeischmidt. Then, that turned it into a chocolate paradise and how it got its nickname, "Wonka's Paradise". Even the flights to Lubenstaraguntenfeischmidt are now equipped with XXXXXXXXL seats, so that even the fattiest of the fattiest of all the fatties can be comfertable. Now not all of Lubenstaraguntenfeischmidt is all chocolate. The outskirts were never hit with chocolate which leaves them with one choice: Nightclubs. From Salsa to Xandudian Extreme Metal its the dancer's paradise. Of course, they all are 24/7 for your convenience. Regarding language, German is spoken, but with Jupiteranian, you'll be allright.
Olympus Mons - a cultural symbol of Mars. The mountain is three times higher than Mount Everest on Earth, and the size of its base is expansive. A popular tourist attraction for those visiting Tempe.
Valles Marineris - Before Mars was terraformed, the valley was like the Grand Canyon of Arizona on crack. After terraformation, the valley is now a body of water, with costal cities such as Xanthe , Hebes, Noctis, Ganges, and Eos. Located at the equator, the area around the Marineris sea is by far the most densly populated area of Mars.
Nunanarambanga - In the poles of Mars at -55555 degrees, stands Nunanarambanga, a monument to President Uaranidiot Anafreek of Marujarandanga-Jazimora, a short-lived country of 0.0001 sq. kilometers and only one day of life. Mr. Anafreek was one of the most great leaders of the world: he cried in front of the Emperor of Tempe and did a temper tantrum not standing the shrieks of him, he gave him Marujarandanga-Jazimora. He was so happy he kissed the Emperor. After the guards found him, they executed him.
Like Earth, Mars has a wide variety of languages. All languages on Mars derive from Earth languages, however, they are heavily dialectized and are sometimes hard to understand.
Martian cuisine is diverse and differs from nation to nation, although the taste of the cuisine is not palatable to the human tongue, such as McDonald's with mixed sparrow stew.