With its drystone walls that surround gnarly-trunked olive trees, its neat rows of vines and, in particular, its trulli - ununsual little circular houses with cone-shaped roofs - scattered about, the Valle d'Itria has to be the most original and picturesque in Puglia... but also the most touristy. Martina Franca, Locorotondo and Cisternino may not yet have been taken over by tourism, but the same cannot be said of Alberobello.