How many waterfalls does the river Tagus have?

The Tagus River has several waterfalls, with the most notable being the Cascades of Alcântara and the Cascades of the River Pera. However, the number of waterfalls along the entire length of the river can vary, as many smaller cascades may not be well-documented. Overall, the river is more famous for its historical and scenic significance than for its waterfalls.