Today, tens of thousands of NYC Marathon entrants are probably enjoying the natural high of running through all five boroughs. Here are some great pictures contributed to us via Flickr (tagged "gothamist" on Flickr or added to the Gothamist Flickr Photo Pool), and we've also included some interesting facts below:

• Geoffrey Mutai, the men's champion who set a course record in 2:05:06, had set a marathon world record earlier this year by running the Boston Marathon in 2:03:02, but since Boston's course is downhill, the record wouldn't stand. Also, the NY Times reports, "For 10 years, Mutai has been his own coach. In 2004, he made a painful decision when he was not winning enough to afford treatment for a leg injury. He went to work cutting trees for Kenya Power, the nation’s utility company."
• Runner's World calls women's champ Firewihot Dado "the overlooked, the uncelebrated, the almost invisible." Not much is known about her, except she did win the Rome Marathon in 2009, 2010 and 2011.
• This year, the Marathon added 74th Street, between 6th and 7th Avenues, in Bay Ridge to its route. According to the Times, "To make sure every racer completes a full 26 miles 385 yards, organizers added a loop through 74th Street."
• A 26-year-old man was in critical condition after collapsing at the 22 Mile marker in Harlem. According to the Post, a witness said, "He fell on his face on Fifth Avenue [near 117th], he just dropped like he was was shot. [Emergency crews] worked on him on Fifth [Avenue] while hundreds of runners passed him." Another witness said, “When the runner was on the ground, he looked bad. He was blue in the face. He did not look good."
• Rangers legend Mark Messier was running in the marathon to raise money for his charities, but after completing the race in 4:14:21, he needed to be taken away in a wheelchair. He's okay though! Other celebrities who ran were Christy Turlington, Apolo Anton Ohno, and Jennie Finch.
• Health Commissioner Tom Farley ran the marathon in 3:25:43.