Rota da Água on Terceira: Angra's water trail from the Nasce Água mills to the Serra do Morião, plus the Passagem das Bestas

Angra do Heroísmo drinks the rain that falls on the hill behind it, and two short official trails let you follow that water uphill. The Rota da Água (PRC12TER) starts at ruined mills on the edge of town and climbs to a viewpoint over Angra and Monte Brasil. The Passagem das Bestas (PRC07TER) loops through the old caldera the water comes from, over rock grooved by centuries of ox carts. Either fills a morning. Both together make a full walking day within a short drive of Angra.

• Short on time, staying in Angra: the Rota da Água. It starts closest to town and takes about two hours.
• Want the caldera, the cart ruts and more forest: the Passagem das Bestas, about two and a half hours.
• Clear weather and a whole day: do the Rota da Água in the morning and the Passagem das Bestas after lunch.

Both are graded medium. Neither is long, but both climb on rough, often wet ground.

• Length and time: 4.2 km, about 2 hours.
• Grade: medium.
• Shape: there and back. The official page calls it circular, but you return on the path you came up, apart from a small detour halfway.
• Start: the Nasce Água area just outside Angra, by the ruins of five mills. The leaflet gives the start as 38° 40' 47" N, 27° 12' 46" W.

The five ruined mills at the start were part of a much bigger system. More than 40 mills once worked along the Ribeira dos Moinhos, the water channel these five stood on. Water mills go back to the beginning of Angra: in the 1460s Álvaro Martins Homem, the town's founder, used water from an artificial ravine to turn his mill wheels on the hill now called Alto da Memória, which is how the old castle there came to be known as the Castle of Moinhos (mills).

From the mills the path climbs the south side of the Serra do Morião, which reaches 602 m. The leaflet's height profile starts at roughly 200 m and turns round above 500 m, so most of the 2 km up is a steady climb.

What you walk through is the city's water supply, and part of the route crosses a restricted area around the catchment. The trail is laid out to show the whole cycle: damp Atlantic air drops its rain inside the Caldeira de Guilherme Moniz, the water sinks into the volcano, and it comes out again as springs on the outer slope, where it is collected, treated and piped to Angra. The plants matter here. Azorean heather (Erica azorica), Azores laurel (Laurus azorica) and the mountain blueberry Vaccinium cylindraceum hold the rain and filter it before it reaches the springs.

Points along the way:

• The Mãe-de-Água spring. Next to it is the first of Angra's three small hydroelectric plants, which together produce about 1% of the island's electricity.
• A water regulation tank halfway up, which collects the water from the Furna d'Água and Cabrito springs.
• The Cruzeiro da Serra da Costaneira, a large cross with an inscription to the effect that there is no true progress outside the Christian faith. It reflects the beliefs of the engineer José Luís Abecassis, who was behind the water project.
• The Morião viewpoint at the top, over Angra, Monte Brasil and the south coast.

Turn round at the viewpoint and come back the same way.

• Length and time: 4 km, about 2 hours 30 minutes.
• Grade: medium.
• Shape: circular.
• Start: a car park by the road, at 38° 42' 34" N, 27° 10' 51" W according to the leaflet. That is about 4 km in a straight line north-east of the Rota da Água start.

This loop lies entirely inside the Caldeira de Guilherme Moniz, which is both an Azores Geopark geosite and a protected area managed for its water. The caldera is a collapse crater about 4 by 2.5 km, stretched from north-west to south-east. Its southern wall is the Serra do Morião you climbed on the Rota da Água. Its flat floor was flooded about 2,000 years ago by basalt lava from the Algar do Carvão cone, the cave you can visit nearby.

The walk starts across an old lava field, rough and uneven underfoot. At the first fork keep left, and you are on the Passagem das Bestas itself: grooves worn into the rock by ox carts that came into the caldera for firewood for centuries. Follow the ruts down into a stream bed until you reach a pipe. It feeds the same small hydroelectric plants you passed on the Rota da Água.

From there the path runs beside a wood of Japanese cedar, passes a viewpoint and crosses a pasture. On the left, between the Serra da Ribeirinha and the Serra do Cume, is the Cinco Picos caldera. At about 7 km across on average, the leaflet calls it the largest in the Azores. A forest edge then leads to the high point of the loop on the Morião. The descent goes through native woodland of Azorean heather and Azores juniper (Juniperus brevifolia), with one viewpoint towards Terra Brava and another into the Guilherme Moniz caldera. You come down the ravine people once used to get into the caldera, rejoin the cart ruts and turn left at the first fork back to the car park.

The heath and peat bogs in this caldera are what recharge the aquifer under it, so stay on the marked path.

• Trail status. On 19 October 2026 neither trail was on the official alerts page; the only Terceira trail listed there was the Serreta circuit (PRC03TER), which was closed. Look at trails.visitazores.com before you set out.
• Weather. Both trails go up into the cloud. The official page warns that the Rota da Água is slippery, especially after rain. Wear boots with grip and take a rain layer in any month. If the hills behind Angra are in cloud, you will see little from the Morião viewpoint.
• Getting there. You need a car or a taxi. We found no bus timetable to Nasce Água or to the Passagem das Bestas car park. Download the GPX tracks from the official trail pages before you leave.
• Rules. Tell someone which trail you are walking and when, do not take shortcuts, and close every gate you open. Leave plants where they are: both trails are in the Terceira Natural Park. In an emergency, call 112.

From Angra, walk the Rota da Água in the morning. Have lunch in town, then drive up for the Passagem das Bestas in the afternoon. That is about four and a half hours of walking. If you would rather have one walk and one sight, swap the second walk for the Algar do Carvão volcanic chimney, whose lava flooded the caldera floor (our caves guide has the opening days). Back in town, the Alto da Memória obelisk, finished in 1856 on the site of the old mill castle, is where the water story started; our Angra guide has the walk up to it. Our hiking guide compares both trails with the rest of the island's official walks.

How long is the Rota da Água on Terceira? 4.2 km there and back, about 2 hours, graded medium. It climbs from roughly 200 m at the Nasce Água mills to a viewpoint above 500 m on the Serra do Morião.

Is the Rota da Água circular? Not really. The official page lists it as circular, but you go up and come back on the same path, apart from a short detour halfway.

What is the Passagem das Bestas? A 4 km circular trail (PRC07TER) inside the Caldeira de Guilherme Moniz, named after the ruts that ox carts wore into the rock while hauling firewood out of the caldera. It takes about 2 hours 30 minutes.

Can you walk both trails in one day? Yes. Together they come to about 8 km and four and a half hours of walking, with a short drive between the two starts.

• Rota da Água (PRC12TER), Azores Trails
• Rota da Água trail leaflet (PDF)
• Passagem das Bestas (PRC07TER), Azores Trails
• Passagem das Bestas trail leaflet (PDF)
• Trail alerts, Azores Trails
• Guilherme Moniz volcano, Azores Geopark (PDF)
• Castle of Moinhos, Wikipedia