World's Longest Miniature Railroad. The City of San Antonio Can rightfully boast of having one of the most unique scale model miniature railroad attractions ever to be seen by the people of San Antonio and visitors alike. This attraction is located in Brackenridge Park an is known as the "Brackenridge Eagle". The "Brackenridge Eagle" is the longest miniature train ride in ht world, and has the combined advantages of transportation sightseeing, and amusement. The train itself is a one-fifth scale model of the diesel-type passenger trains developed by General Motors at a cost of several million dollars and commonly used today by the Missouri-Pacific RR. It is exact in all details down to the most minute part, some of which are air brakes on each wheel, air horns. springs, bell, lights, ladders, windows, and many other realistic details. It is fascinating and educational realistic details. It is fascinating and educational to merely inspect such a piece of craftsmanship. The scenic route taken by this train is over three miles in length, crossing the San Antonio river two times, passing through a tunnel over one hundred feet long, meandering through a beautiful wooded area on gentle curves, and making several stops at various points of interest in the park. 72% of the passengers are adults.