Siena is a medieval city in Tuscany, whose historic centre is a UNESCO World Heritage Site. In it, the traditional horse race named Il Palio takes place twice a year since 1633, in July and August. Ten horses and riders, who represent ten of the seventeen city quarters called contrade (contrada, in the singular form), compete in the 90-second race around Piazza del Campo. The contest is more than a competition as it is part of the pride of the city itself which relies on the rivalry of each ward. 

Siena is also home to Monte dei Paschi. Founded in 1472, the oldest bank in the world has nurtured an exclusive relationship with Il Palio which is based not only on its philanthropic mission but also on a creditor-debtor link. 
In fact, during the phases immediately before the start of the run, jockeys are involved in a sort of chaotic diplomatic negotiations in order to get cooperation from their peers to come in first. For reaching this goal, they have also a budget to manage and can eventually pay a sum comprised between half a million and a million euros. 
The day after, the winner heads to the bank to ask for a loan and pay his creditors. Among the thousands of clients of the bank, the contrade have been the most solvent ones as the future political stability of the city itself relies on their ability to pay back their loans. To some extent, it could be argued that Il Palio represents a kind of ante litteram blockchain.