Located in Porto’s historic center, the 76-meter-tall Torre dos Clérigos is the bell tower of an adjacent church, both of which were designed by Baroque architect Nicolau Nasoni in the mid-18th century. An iconic landmark of the city, it was once used as a reference point for boats entering the Douro. The tower offers marvelous views of the river and the city of Porto—which you can experience if you brave the 240-step climb to the top.