Workaway and HelpX connect travellers with locals who are looking for help from volunteers around the globe and in exchange, they provide free stay and meals {some even give a stipend}. You could help out with canoeing and other activities at a picturesque campsite in Prague or work at an eco-lodge in Chiang Mai that rescues elephants. Volunteering is indeed a great way to travel affordably as well as gather unique experiences.
Disclaimer: The visa and volunteer work prerequisites are subject to country laws. Please check with the travel companies/ concerned embassies before applying.