The town's name probably derive from the word "gabbia" (cage), which is also the equivalent to a private fenced property. Municipality located at more than a thousand meters of altitude on the border with Piedmont Region, the town is situated in a valley at the foot of Colle della Vecchia and Colle Mologna, washed by the river Lys. It is a popular touristic resort for all the Seasons: in Summer thanks to its cool climate and in Winter thanks to its proximity to the skiing area of Monterosa. The municipal territory includes several villages, which at the highest point reach more than 3000 meters near the Becca Frudiera. Typical of the area is the village of Niel, located behind the town, in the Valley, from where it is possible to admire the traditional Valdostane style houses (stadel Walser).
The territory was inhabited in pre-Roman times by the Salassi, like elsewhere in the region. This population was formed by a mixture of local inhabitants and the ancient Celt tribes, that arrived in the Val d'Aosta region from central Europe, between the VIII and V centuries B.C. The influence of the Celts on Gaby is still present in the local dialect widespread among the inhabitants, which betrays the influence of other ethnic groups. The territory became a Roman possession in 25 B.C. After defeating the Salassi and enslaved them, the Romans seized the land and distributed them and the sacked funds among the centurions. The lands were named after those to which they had been assigned. In the medieval period various feudal noble families exercised their power in the territory. In 1952 the town was newly established and rebuilt. Until that year it was known as Issime Saint Michel and was a large district of the town of Issime.

Not to miss:

The Parish Church of San Michele that features the key dates in the history of the church on the portal. The present building was erected in 1824 on an earlier chapel too small to hold all the faithful. The Baroque altar of the original chapel, built in 1748, became a side altar. It retains a canopy, designed by Carlo Delponte, in Baroque style, above the main altar and a series of frescoes and decorations of the artist Morgari Martinelli.
The Vourry shrine, dedicated to the Lady of Grace depicted in a fresco on the façade. It was built in 1833 in place of the original chapel, which had two altars and a tower. The current structure preserves a remarkable inlaid portal, a wooden carved and gilded altar in Baroque style and an XVIII century organ. Worth of mention are the fourteen Stations of the Cross painted by Francesco Curtaz.