1 / 4   To pay tribute to military veterans, around 400,000 motorcyclists across the US gathered in Washington, DC for the 31st annual Rolling Thunder Ride for Freedom on 27 May morning. /VCG Photo

2 / 4   “This is beyond belief. All the people here are vets or honoring vets,” said Ken Rudder, a Navy veteran said to WTOP-FM, a Washington-based radio station. /VCG Photo

3 / 4   Rows of bikes have lined up since Saturday afternoon around places including Lincoln Memorial, Constitution Avenue and Capitol Hill. A dog was also dressed up as a solider. /VCG Photo

4 / 4   Hundreds of fans stood on both sides of the road, waving the American flag. American flags as well as the black and white POW/MIA flags feature the silhouette of a bowed head and the word, “You Are Not Forgotten.” /VCG Photo