Mosteiro da Serra do Pilar

The Serra do Pilar monastery stands on the Gaia side of the Douro directly above the Dom Luís I bridge, and it is architecturally unusual: both its church and its cloister are circular, a plan almost unique in Portugal, built between 1538 and 1670 for the Augustinians. Its position made it a fortress repeatedly - Wellington's forces used it in 1809 to observe the French across the river before crossing, and it was a key position again in the 1832 siege during the civil war, when it was heavily damaged. It is still partly held by the army. The terrace outside is what most people come for: the standard photograph of Porto, with the double-deck bridge in the foreground, the Ribeira houses stacked on the far bank, the port lodges below and the river running west. It is UNESCO-listed as part of the Porto historic centre.

What you actually see

• The circular church and cloister - a round plan almost unique in Portugal.
• The terrace view - the Dom Luís bridge, the Ribeira and the Douro in one frame.
• The military history - a position used by Wellington in 1809 and besieged in 1832.
• The 1538 to 1670 build - an Augustinian house that took over a century.

When to go

Year-round. One hour. Sunset is the crowded time on the terrace; morning gives better light on the Ribeira opposite.

Honest expectations

The terrace is free but the church and cloister are ticketed and keep limited hours, closing on some days. Part of the complex is army property and closed. The terrace is packed at sunset with buskers and sellers. Walking the bridge's upper deck means sharing it with the metro.

Nearby

The Gaia port lodges are below; the Ribeira is across the bridge.