The Ucanha Tower, in the municipality of Tarouca, has been classified as a national monument since 1910 by the IPPAR.
In the past, the Tower was used for the defence of the medieval bridge, the control of people and goods and also the collection of tolls, whose income benefited the county of Salzedas. The tolls were however abolished in 1504 and the tower lost much of its importance as the building went into decline and used as a warehouse for products. The bridge however continued to be used as one of the main crossing points for the river.