South of Siena the Tuscan hills lose their vines and cypress and turn into something stranger: the Crete Senesi, a landscape of bare, rounded clay hills the colour of a wet pigeon, cut by gullies that geologists call calanchi. Asciano is the town that sits at the heart of it. It is a compact brick-and-stone place inside medieval walls, with a handful of churches, a small collection of Etruscan and sacred art in its museums, and a main street that the locals walk up and down in the evening. Nobody comes to Asciano for a famous monument, and that is the nice thing about it.
The country around is the draw. In spring the clay slopes turn a soft, bright green with young wheat, in early summer they ripen to gold, and after the harvest the fields are ploughed to a grey-brown that can look like the surface of the moon. Single farmhouses, each ringed by a few cypresses, stand on the ridges like ships. Riding through this country is slow and pleasant, with long gentle gradients, wide views and not much in the way of traffic once you leave the main roads. The tarmac is generally fine, though some of the side roads turn to white gravel, the strade bianche that cyclists race on, and a loose surface needs some respect on a road bike.
The clay is no accident of nature in a simple sense. The hills are the bed of an ancient sea, and the sediments laid down there erode into the characteristic gullies when the rains come, which is why the farmers here have always fought a battle with the soil. In summer it bakes hard and cracks, and in wet weather the unpaved tracks become slippery, so that is another reason to be wary of leaving the asphalt.
Asciano has the services of a working Tuscan town. There are fuel stations on the approach roads, a supermarket, bakeries and a good choice of simple restaurants, where the local specialities are pici, thick hand-rolled pasta, boar sauce, pecorino cheese and the honey of the district. A train line links the town to Siena. Sinalunga, about fifteen kilometres to the east, is a larger town and handy if you need something more.
The best time to come is spring or early autumn. Midsummer is hot and a bit flat, but the light at the end of the day is lovely on the clay.