The best traffic-free bike rides around Retiers

To see the medieval castle (its ruins anyway)

Long greenway between Châteaubriant and Bain de Bretagne. Very smooth rolling.

Unusual dimensions for a dolmen. I visited it on a weekday and had the site all to myself. Truly impressive. Also worth seeing is the chestnut tree at the entrance, which tried - but apparently failed - to swallow a megalith at the entrance to the dolmen. Toilets with a tap. Benches.

Magnificent greenway, rolling and shaded. Less flat than I expected.

Church attested in the 12th century. Nave flanked by a north aisle, built between 1540 and 1549 (date of consecration by the bishop of Rennes), and by a south aisle, built between 1603 and 1605 (dates inscribed). Inscription on the south door: ESTANT NOBLE ET DISCRET PRESTRE : RENE DE L'ESPINAY RECTEUR DE PIRE : SIEUR DE LA GUAYE FUT CESTE EDIF : CE COMMENCE. SA (NC) TE DEUS SA (NC) TE FORTIS SA (NC) TE IMORTALIS MISERERE NOBIS SA (NC) TE PETRE ORA P (RO) NOBIS : TOUT EST A Dieu 1603. The choir was first rebuilt in 1627, then surmounted by a dome struck by lightning in 1741, then again between 1752 and 1775, flanked by side sacristies. Bell tower at the top of the nave rebuilt in 1669. In 1874, architect Aristide Tourneux had a bay added to the north of the nave and a porch-tower surmounted by a spire built. Stained glass windows signed and dated: Claudius Lavergne 1882, and also stained glass windows from the Rault workshops and the Carmel of Le Mans. South wall of the enclosure redone in the 19th century with a monumental corner staircase.

Church built in the 15th century, from that period only the choir and the chapel to the north, which became the sacristy, currently remain. The nave and transept were rebuilt in 1851 (inscription: MR. RUPIN MAIRE ET LES PAROISSIENS 1851). The tower is dated 1859, it was built by Guyon, an entrepreneur from Vitré.

The bell tower is visible from afar and has long dominated the town and its surroundings. The Saint-Pierre church has retained its impact on the local landscape for over a century. It was indeed in 1888 that the Fabrique Council decided to entrust Arthur Régnault, the diocese's architect, with the project for a new construction. His plan was accepted and work began in October 1889, before the blessing of the first stone on March 13, 1890. As an anecdote, the stones are extracted from the quarry of La Bouëxière. Quickly, the inhabitants discovered its citadel-like appearance, Arthur Régnault having wanted to honor the city of Châteaubourg which had not had a castle for a long time! The structural work was completed on March 28, 1893, but due to lack of funds, the bells would wait until 1894. The work on the woodwork and the construction of the high altar took place in 1911, the church being due to host the important Eucharistic congress of 1913. Maintenance work continued over the years, the church having become the property of the municipality since 1905. During the bombings of the summer of 1944, the church was spared. The inhabitants would not forget it: on May 9, 1945, the day after the armistice, the men carried Notre Dame de Boulogne in procession and paraded barefoot through the streets. The centenary was celebrated in 1992 with the decision to install the current organ. The church of Châteaubourg has thus traversed local history from the 15th century – the date of construction of the previous, much smaller church – to that designed by Arthur Régnault.

The sacristy and tower of the current church were built in 1628 and 1632. A chapel was dedicated to Saint Nicholas in 1643. As for the nave, it dates from 1856. It contains a carved wooden altarpiece, bearing the coat of arms of Brignon, one of the church's financiers.