The old part of Tours crowds around place Plumereau , over to the west of rue Nationale. Between the two, the Hôtel Gouin , 25 rue du Commerce, has a Renaissance facade to stop you in your tracks. Inside, it exhibits a surprising collection for an archeological museum, including a medicine chest belonging to Jean-Jacques Rousseau, and examples of early technical advances in physics, such as the Archimedes screw and a vacuum pump (mid-May to Sept daily 10am-7pm; Oct to mid-March daily except Fri 10am-12.30pm & 2-5.30pm; rest of year daily 10am-12.30pm & 2-6.30pm; 20F/¬3.05).

 

But it's the old town's half-timbered houses and bulging stairway towers dating from the twelfth to fifteenth centuries that are the city's showpiece. Some of the earlier buildings look like cut-out models, but the Renaissance stone-and-brick constructions are sturdier - particularly the Écoles des Langues Vivantes on rue Briconnet, with its wonderful sculpted dogs, drunks, frogs and monsters. West of rue Bretonneau, around place Robert-Picou, modern artisans' workshops cluster between medieval dwellings.

Off rue Briconnet, at 7 rue du Mûrier, you'll find the Musée du Gemmail (mid-March to mid-Oct Tues-Sun 10am-noon & 2-6.30pm; 30F/¬4.57), a museum of non-leaded stained glass. Some of the works are displayed in an underground twelfth-century chapel, and artists include such leading artists as Picasso and Jean Cocteau. Their works shine with an extraordinary intensity and, through the use of layering, have a far greater colour range than traditional stained glass.

To the south, an enormous church once stood, with its nave stretching along rue des Halles from rue des Trois-Pavées-Ronds almost to place de Châteauneuf. Only the north tower, the Tour de Charlemagne, and the western clock tower remain of the ancient Basilique de St-Martin . The new church, a late nineteenth-century neo-Byzantine affair, guards the shrine of St Martin, bishop of Tours in the fourth century and famous for giving half his cloak to a freezing beggar.