Altoona is a city in the Alleghenies region of Pennsylvania. It is the tenth most populous city in the state and is located in Blair County. The city was founded in 1849 and has a population of around 46, 000 people. ALTOONA is known for its railroad history, as it was once a major hub for the Pennsylvania Railroad. It is also home to the Horseshoe Curve National Historic Landmark, which is a curved section of track that was built in 1854.