S. Martino a Mensola is very old, for it is said that in the year 800 an oratory stood here, dedicated to S. Martino, and that il Beato Andrea di Scozia, Blessed Andrew of Scotland, then archdeacon to the bishopric of Fiesole, rebuilt it and endowed a little monastery, where he went to live with a few companions, taking the rule of St. Benedict.  Carocci tells us that about 1550 it passed from the Benedictines to certain monks who already had a house at S. Andrea in Mercato Vecchio of Florence.  In 1450 the monastery returned to Benedictines, coming into the possession of the monks of the Badia.  Restored many times, the church was rebuilt in the fifteenth century, it may well be by Brunellesco; the portico, restored in 1857, was added in the sixteenth century.  Within, the church is charming, having a nave and two aisles, with four small chapels and a great one, which belonged to the Zati family.  And then, not without a certain surprise, you come here upon many pictures still in their own place, over the altars of what is now a village church.  Over the high altar is a great ancona divided into many compartments:  the Virgin with our Lord, S. Maria Maddalena, S. Niccolo, St. Catharine of Alexandria, S. Giuliano, S. Amerigo of Hungary, S. Martino, S. Gregorio, S. Antonio, and the donor, Amerigo Zati.  Carocci suggests Bernardo Orcagna as the painter; whoever he may have been, this altarpiece is beautiful, and the more beautiful too since it is in its own place.  In the Gherardi Chapel there is an Annunciation given to Giusto d’Andrea, while in another is a Madonna and Saints by Neri di Bicci.  In the chapel of the Cecchini there is a fine fifteenth-century work attributed to Cosimo Rosselli.  The old monastery is to-day partly the canonica and partly a villa.  Following the stream upwards, we pass under and then round the beautiful Villa I Tatti that of old belonged to the Zati family whose altarpiece is in S. Martino, and winding up the road to Vincigliata, you soon enter the cypress woods.  All the way to your left Poggio Gherardo has towered over you, Poggio Gherardo where the two first days of the Decamerone were passed.  How well Boccaccio describes the place:  “On the top of a hill there stood a palace which was surrounded by beautiful gardens, delightful meadows, and cool springs, and in the midst was a great and beautiful court with galleries, halls, and rooms which were adorned with paintings....”  Not far away, Boccaccio himself lived on the podere of his father.  You come to it if you pass out of the Vincigliata road by a pathway down to Frassignaja, a little stream which, in its hurry to reach Mensola, its sister here, leaps sheer down the rocks in a tiny waterfall.  This is the “shady valley” perhaps where in the evening the ladies of the Decamerone walked “between steep rocks to a crystal brook which poured down from a little hill, and there they splashed about with bare hands and feet, and talked merrily with one another.”  Crossing this