As Catedrais Beach at Low Tide, with the Xunta's Free Authorisation

As Catedrais, or Augas Santas, is a beach in Ribadeo enclosed by slate cliffs in which the sea has opened arches, caves and corridors. It is a natural monument, and can only really be explored at low tide: at high tide the water covers the whole beach for hours. Going down is free all year, but at Easter and from 1 July to 30 September the Xunta requires an authorisation, also free, obtained on its website.

The authorisation, step by step

In the two periods with reservations you enter the beach with a named permit for a specific day. It is requested at ascatedrais.xunta.gal, at most 30 days before the visit; the website doesn't let you book earlier. One person can request it for a group of up to 25, but must give everyone's details: first name and surname, sex, year of birth and identity document. Under-14s don't need a document. The permit is valid only for that day and for the people named in it, and there is a permanent checkpoint on the stairs down.

If the quota is full, Turismo de Ribadeo publishes three other routes. If you are sleeping in Ribadeo, your accommodation may give you a pass. The summer shuttle bus, the Bus Praia, leaves from Ribadeo bus station and its ticket serves as authorisation; the colour of the outward ticket must match the return time. And if you arrive by taxi, the receipt is valid as a permit. Outside those dates nothing is needed: you arrive and go down. The restriction affects only the descent to the sands; the paths and viewpoints above are open.

The Xunta also organises free guided visits with official guides, in groups of up to 25, which are requested along with the authorisation. Their times change each day with the tide. If you are already on the beach and didn't request it, ask the guide whether places remain.

The tide rules

The Xunta recommends going down between two hours before and two hours after low tide; the booking website tells you the time when you choose the day. Turismo de Ribadeo is more precise: arrive one hour before low tide and go first to the right when you come down the stairs, about 600 metres, because the area of the arches is the last to be uncovered and the first to be covered. Spring tides, around the full and new moon, leave more sand in view; with neap tides you may not reach the arches even if you go at low tide.

Don't go near the base of the arches or enter the caves: it is a cliff that sheds rock, especially after heavy rain. If the tide cuts off your way, don't cross through the water. Wear shoes that grip on wet rock and take something warm.

Getting there and parking

The beach is about 10 minutes from Ribadeo along the N-634 and has its own exit on the A-8, number 516. There are three car parks; the farthest is less than a kilometre from the entrance. By train, the Ferrol–Xixón line stops at Esteiro, 10 minutes' walk away. In summer, the Bus Praia saves you looking for a space. On the beach there is a tourist information point at Easter and from 1 July to 30 September. To see it from the sea without depending on the tide, see the boat to As Catedrais from Ribadeo.