Marathons are long-distance running races of over 26 miles and are great exercise!
Wow! thats cool! Ive been actually training for a marathon recently, DO you know if a marathon is on a flat road or are there any hills? 
I think they are generally flat, but the event was made to commemorate the run of Pheidippides, a Greek soldier who relayed the victory of the Battle of Marathon to Athens.
Oh ok, I just hope it wont be too hard, I can only run so much up a hill lol. What kinda age limit is there for a marathon i any? 
There aren't any age limits. In fact of the more than 800 marathons held in the world each year, the majority of competitors are recreational athletes.
Wow over 800!!? thats wild. Do you know what the world record is for running in a marathon? Im sure people have broken that 26 mile limit. 
I'm not sure what the world record is but the marathon was one of the original modern Olympic events which dates back to 1896.
Fascinating, Never really thought of a marathon as an Olympic sport, What are some famous marathon runners that competed?
just fought), which took place in August or September, 490 BC. It is said that he ran the entire distance without stopping and burst into the assembly, exclaiming ("nenikēkamen", "we have won!"), before collapsing and dying. The account of the run from Marathon to Athens first appears in Plutarch's "On the Glory of Athens" in the 1st century AD, which quotes from Heraclides Ponticus's lost work, giving the runner's name as either Thersipus of Erchius or Eucles.
Road running
Road running is the sport of running on a measured course over an established road (as opposed to track and field and cross country running).
These events are usually classified as long-distance according to athletics terminology, with races typically ranging from 5 kilometers to 42.2 kilometers in the marathon. They may involve large numbers of runners or wheelchair entrants. The three most common IAAF recognized distances for "road running" events are 10K runs, half marathons and marathons. Despite this, there are far