The local government of Siena have always been a progressive bunch – it was they who commissioned the famous cycle of three fresco paintings Allegory and Effects of Good and Bad Government for the walls of the Palazzo Publico (Town Hall) in the 14th century which were groundbreaking in their non-religious subject matter (you can still see these paintings today), and they continue to come up with good ideas in the 21st century.
My favorite is the series of Urban Trekking Guided Walks that they have put online for visitors to Siena. One is for kids, called Trekking for Young Explorers and written in language to appeal to children, it encourages young walkers to take photos, to draw what they see along the way, to count steps and so on, as well as introducing history as stories and adventures from the past. Others are aimed at adults and take similar paths but in more sophisticated language. One focuses on Nature and Art, following a route between parks, landscape views and churches containing some significant paintings of the Senese school of Renaissance art. Another leads to great views by following the Via Francigena which is the old pilgrimage path between Northern Europe and Rome. A final one is on Alleys and Gardens in the Shadow of the Tower tracing the history of Siena’s inhabitants from working class neighborhoods to the wealthy homes of the city’s leaders. All are printable PDF files and clearly marked with places to stop and read the information, view points, length and difficulty etc, as well as points where you can check the indicators of air quality.