Complex sentence: The train system's tunnels are home to two of the airport's visual art exhibits.the art installations were created since the November of 2005, nearly one percent of the total budget for the construction of Denver International Airport was dedicated to artwork.
Split into simpler sentences: The train system's tunnels are home to two of the airport's visual art exhibits. These art installations were created since nearly one percent of the total budget for the construction of Denver International Airport was dedicated to artwork.